diff --git a/src/pocketmine/level/format/Chunk.php b/src/pocketmine/level/format/Chunk.php
index f55bb9862..a9ec75a0d 100644
--- a/src/pocketmine/level/format/Chunk.php
+++ b/src/pocketmine/level/format/Chunk.php
@@ -39,6 +39,8 @@ use pocketmine\utils\ChunkException;
 
 class Chunk{
 
+	const MAX_SUBCHUNKS = 16;
+
 	/** @var LevelProvider */
 	protected $provider;
 
@@ -53,7 +55,7 @@ class Chunk{
 	protected $terrainGenerated = false;
 	protected $terrainPopulated = false;
 
-	protected $height = 16;//Chunk::MAX_SUBCHUNKS;
+	protected $height = Chunk::MAX_SUBCHUNKS;
 
 	/** @var SubChunk[] */
 	protected $subChunks = [];
@@ -137,10 +139,16 @@ class Chunk{
 		$this->NBTentities = $entities;
 	}
 
+	/**
+	 * @return int
+	 */
 	public function getX() : int{
 		return $this->x;
 	}
 
+	/**
+	 * @return int
+	 */
 	public function getZ() : int{
 		return $this->z;
 	}
@@ -149,26 +157,60 @@ class Chunk{
 		$this->x = $x;
 	}
 
+	/**
+	 * @param int $z
+	 */
 	public function setZ(int $z){
 		$this->z = $z;
 	}
 
+	/**
+	 * @return LevelProvider|null
+	 */
 	public function getProvider(){
 		return $this->provider;
 	}
 
+	/**
+	 * @param LevelProvider $provider
+	 */
 	public function setProvider(LevelProvider $provider){
 		$this->provider = $provider;
 	}
 
+	/**
+	 * Returns the chunk height in count of subchunks.
+	 *
+	 * @return int
+	 */
 	public function getHeight() : int{
 		return $this->height;
 	}
 
+	/**
+	 * Returns a bitmap of block ID and meta at the specified chunk block coordinates
+	 *
+	 * @param int $x 0-15
+	 * @param int $y
+	 * @param int $z 0-15
+	 *
+	 * @return int bitmap, (id << 4) | meta
+	 */
 	public function getFullBlock(int $x, int $y, int $z) : int{
 		return $this->getSubChunk($y >> 4)->getFullBlock($x, $y & 0x0f, $z);
 	}
 
+	/**
+	 * Sets block ID and meta in one call at the specified chunk block coordinates
+	 *
+	 * @param int      $x 0-15
+	 * @param int      $y
+	 * @param int      $z 0-15
+	 * @param int|null $blockId 0-255 if null, does not change
+	 * @param int|null $meta 0-15 if null, does not change
+	 *
+	 * @return bool
+	 */
 	public function setBlock(int $x, int $y, int $z, $blockId = null, $meta = null) : bool{
 		if($this->getSubChunk($y >> 4, true)->setBlock($x, $y & 0x0f, $z, $blockId !== null ? ($blockId & 0xff) : null, $meta !== null ? ($meta & 0x0f) : null)){
 			$this->hasChanged = true;
@@ -177,30 +219,81 @@ class Chunk{
 		return false;
 	}
 
+	/**
+	 * Returns the block ID at the specified chunk block coordinates
+	 *
+	 * @param int $x 0-15
+	 * @param int $y
+	 * @param int $z 0-15
+	 *
+	 * @return int 0-255
+	 */
 	public function getBlockId(int $x, int $y, int $z) : int{
 		return $this->getSubChunk($y >> 4)->getBlockId($x, $y & 0x0f, $z);
 	}
 
+	/**
+	 * Sets the block ID at the specified chunk block coordinates
+	 *
+	 * @param int $x 0-15
+	 * @param int $y
+	 * @param int $z 0-15
+	 * @param int $id 0-255
+	 */
 	public function setBlockId(int $x, int $y, int $z, int $id){
 		if($this->getSubChunk($y >> 4, true)->setBlockId($x, $y & 0x0f, $z, $id)){
 			$this->hasChanged = true;
 		}
 	}
 
+	/**
+	 * Returns the block meta value at the specified chunk block coordinates
+	 *
+	 * @param int $x 0-15
+	 * @param int $y
+	 * @param int $z 0-15
+	 *
+	 * @return int 0-15
+	 */
 	public function getBlockData(int $x, int $y, int $z) : int{
 		return $this->getSubChunk($y >> 4)->getBlockData($x, $y & 0x0f, $z);
 	}
 
+	/**
+	 * Sets the block meta value at the specified chunk block coordinates
+	 *
+	 * @param int $x 0-15
+	 * @param int $y
+	 * @param int $z 0-15
+	 * @param int $data 0-15
+	 */
 	public function setBlockData(int $x, int $y, int $z, int $data){
 		if($this->getSubChunk($y >> 4)->setBlockData($x, $y & 0x0f, $z, $data)){
 			$this->hasChanged = true;
 		}
 	}
 
+	/**
+	 * Returns the raw block extra data value at the specified chunk block coordinates, or 0 if no data exists
+	 *
+	 * @param int $x 0-15
+	 * @param int $y
+	 * @param int $z 0-15
+	 *
+	 * @return int bitmap, (meta << 8) | id
+	 */
 	public function getBlockExtraData(int $x, int $y, int $z) : int{
 		return $this->extraData[Chunk::chunkBlockHash($x, $y, $z)] ?? 0;
 	}
 
+	/**
+	 * Sets the raw block extra data value at the specified chunk block coordinates
+	 *
+	 * @param int $x 0-15
+	 * @param int $y
+	 * @param int $z 0-15
+	 * @param int $data bitmap, (meta << 8) | id
+	 */
 	public function setBlockExtraData(int $x, int $y, int $z, int $data){
 		if($data === 0){
 			unset($this->extraData[Chunk::chunkBlockHash($x, $y, $z)]);
@@ -211,26 +304,69 @@ class Chunk{
 		$this->hasChanged = true;
 	}
 
+	/**
+	 * Returns the sky light level at the specified chunk block coordinates
+	 *
+	 * @param int $x 0-15
+	 * @param int $y
+	 * @param int $z 0-15
+	 *
+	 * @return int 0-15
+	 */
 	public function getBlockSkyLight(int $x, int $y, int $z) : int{
 		return $this->getSubChunk($y >> 4)->getBlockSkyLight($x, $y & 0x0f, $z);
 	}
 
+	/**
+	 * Sets the sky light level at the specified chunk block coordinates
+	 *
+	 * @param int $x 0-15
+	 * @param int $y
+	 * @param int $z 0-15
+	 * @param int $level 0-15
+	 */
 	public function setBlockSkyLight(int $x, int $y, int $z, int $level){
 		if($this->getSubChunk($y >> 4)->setBlockSkyLight($x, $y & 0x0f, $z, $level)){
 			$this->hasChanged = true;
 		}
 	}
 
+	/**
+	 * Returns the block light level at the specified chunk block coordinates
+	 *
+	 * @param int $x 0-15
+	 * @param int $y 0-15
+	 * @param int $z 0-15
+	 *
+	 * @return int 0-15
+	 */
 	public function getBlockLight(int $x, int $y, int $z) : int{
 		return $this->getSubChunk($y >> 4)->getBlockLight($x, $y & 0x0f, $z);
 	}
 
+	/**
+	 * Sets the block light level at the specified chunk block coordinates
+	 *
+	 * @param int $x 0-15
+	 * @param int $y 0-15
+	 * @param int $z 0-15
+	 * @param int $level 0-15
+	 */
 	public function setBlockLight(int $x, int $y, int $z, int $level){
 		if($this->getSubChunk($y >> 4)->setBlockLight($x, $y & 0x0f, $z, $level)){
 			$this->hasChanged = true;
 		}
 	}
 
+	/**
+	 * Returns the Y coordinate of the highest non-air block at the specified X/Z chunk block coordinates
+	 *
+	 * @param int  $x 0-15
+	 * @param int  $z 0-15
+	 * @param bool $useHeightMap whether to use pre-calculated heightmap values or not
+	 *
+	 * @return int
+	 */
 	public function getHighestBlockAt(int $x, int $z, bool $useHeightMap = true) : int{
 		if($useHeightMap){
 			$height = $this->getHeightMap($x, $z);
@@ -258,14 +394,31 @@ class Chunk{
 		return $height;
 	}
 
+	/**
+	 * Returns the heightmap value at the specified X/Z chunk block coordinates
+	 *
+	 * @param int $x 0-15
+	 * @param int $z 0-15
+	 *
+	 * @return int
+	 */
 	public function getHeightMap(int $x, int $z) : int{
 		return $this->heightMap[($z << 4) | $x];
 	}
 
+	/**
+	 * Returns the heightmap value at the specified X/Z chunk block coordinates
+	 * @param int $x 0-15
+	 * @param int $z 0-15
+	 * @param int $value
+	 */
 	public function setHeightMap(int $x, int $z, int $value){
 		$this->heightMap[($z << 4) | $x] = $value;
 	}
 
+	/**
+	 * Recalculates the heightmap for the whole chunk.
+	 */
 	public function recalculateHeightMap(){
 		for($z = 0; $z < 16; ++$z){
 			for($x = 0; $x < 16; ++$x){
@@ -274,8 +427,12 @@ class Chunk{
 		}
 	}
 
+	/**
+	 * Performs basic sky light population on the chunk.
+	 *
+	 * TODO: rewrite this, use block light filters and diffusion, actual proper sky light population
+	 */
 	public function populateSkyLight(){
-		//TODO: rewrite this, use block light filters and diffusion, actual proper sky light population
 		for($x = 0; $x < 16; ++$x){
 			for($z = 0; $z < 16; ++$z){
 				$heightMap = $this->getHeightMap($x, $z);
@@ -299,15 +456,37 @@ class Chunk{
 		}
 	}
 
+	/**
+	 * Returns the biome ID at the specified X/Z chunk block coordinates
+	 *
+	 * @param int $x 0-15
+	 * @param int $z 0-15
+	 *
+	 * @return int 0-255
+	 */
 	public function getBiomeId(int $x, int $z) : int{
 		return ord($this->biomeIds{($z << 4) | $x});
 	}
 
+	/**
+	 * Sets the biome ID at the specified X/Z chunk block coordinates
+	 *
+	 * @param int $x 0-15
+	 * @param int $z 0-15
+	 * @param int $biomeId 0-255
+	 */
 	public function setBiomeId(int $x, int $z, int $biomeId){
 		$this->hasChanged = true;
 		$this->biomeIds{($z << 4) | $x} = chr($biomeId & 0xff);
 	}
 
+	/**
+	 * Returns a column of block IDs from bottom to top at the specified X/Z chunk block coordinates.
+	 * @param int $x 0-15
+	 * @param int $z 0-15
+	 *
+	 * @return string
+	 */
 	public function getBlockIdColumn(int $x, int $z) : string{
 		$result = "";
 		foreach($this->subChunks as $subChunk){
@@ -316,6 +495,13 @@ class Chunk{
 		return $result;
 	}
 
+	/**
+	 * Returns a column of block meta values from bottom to top at the specified X/Z chunk block coordinates.
+	 * @param int $x 0-15
+	 * @param int $z 0-15
+	 *
+	 * @return string
+	 */
 	public function getBlockDataColumn(int $x, int $z) : string{
 		$result = "";
 		foreach($this->subChunks as $subChunk){
@@ -324,6 +510,13 @@ class Chunk{
 		return $result;
 	}
 
+	/**
+	 * Returns a column of sky light values from bottom to top at the specified X/Z chunk block coordinates.
+	 * @param int $x 0-15
+	 * @param int $z 0-15
+	 *
+	 * @return string
+	 */
 	public function getBlockSkyLightColumn(int $x, int $z) : string{
 		$result = "";
 		foreach($this->subChunks as $subChunk){
@@ -332,6 +525,13 @@ class Chunk{
 		return $result;
 	}
 
+	/**
+	 * Returns a column of block light values from bottom to top at the specified X/Z chunk block coordinates.
+	 * @param int $x 0-15
+	 * @param int $z 0-15
+	 *
+	 * @return string
+	 */
 	public function getBlockLightColumn(int $x, int $z) : string{
 		$result = "";
 		foreach($this->subChunks as $subChunk){
@@ -340,30 +540,51 @@ class Chunk{
 		return $result;
 	}
 
+	/**
+	 * @return bool
+	 */
 	public function isLightPopulated() : bool{
 		return $this->lightPopulated;
 	}
 
+	/**
+	 * @param bool $value
+	 */
 	public function setLightPopulated(bool $value = true){
 		$this->lightPopulated = $value;
 	}
 
+	/**
+	 * @return bool
+	 */
 	public function isPopulated() : bool{
 		return $this->terrainPopulated;
 	}
 
+	/**
+	 * @param bool $value
+	 */
 	public function setPopulated(bool $value = true){
 		$this->terrainPopulated = $value;
 	}
 
+	/**
+	 * @return bool
+	 */
 	public function isGenerated() : bool{
 		return $this->terrainGenerated;
 	}
 
+	/**
+	 * @param bool $value
+	 */
 	public function setGenerated(bool $value = true){
 		$this->terrainGenerated = $value;
 	}
 
+	/**
+	 * @param Entity $entity
+	 */
 	public function addEntity(Entity $entity){
 		$this->entities[$entity->getId()] = $entity;
 		if(!($entity instanceof Player) and $this->isInit){
@@ -371,6 +592,9 @@ class Chunk{
 		}
 	}
 
+	/**
+	 * @param Entity $entity
+	 */
 	public function removeEntity(Entity $entity){
 		unset($this->entities[$entity->getId()]);
 		if(!($entity instanceof Player) and $this->isInit){
@@ -378,6 +602,9 @@ class Chunk{
 		}
 	}
 
+	/**
+	 * @param Tile $tile
+	 */
 	public function addTile(Tile $tile){
 		$this->tiles[$tile->getId()] = $tile;
 		if(isset($this->tileList[$index = (($tile->x & 0x0f) << 12) | (($tile->z & 0x0f) << 8) | ($tile->y & 0xff)]) and $this->tileList[$index] !== $tile){
@@ -389,6 +616,9 @@ class Chunk{
 		}
 	}
 
+	/**
+	 * @param Tile $tile
+	 */
 	public function removeTile(Tile $tile){
 		unset($this->tiles[$tile->getId()]);
 		unset($this->tileList[(($tile->x & 0x0f) << 12) | (($tile->z & 0x0f) << 8) | ($tile->y & 0xff)]);
@@ -397,27 +627,60 @@ class Chunk{
 		}
 	}
 
+	/**
+	 * Returns an array of entities currently using this chunk.
+	 *
+	 * @return Entity[]
+	 */
 	public function getEntities() : array{
 		return $this->entities;
 	}
 
+	/**
+	 * @return Tile[]
+	 */
 	public function getTiles() : array{
 		return $this->tiles;
 	}
 
+	/**
+	 * Returns the tile at the specified chunk block coordinates, or null if no tile exists.
+	 *
+	 * @param int $x 0-15
+	 * @param int $y
+	 * @param int $z 0-15
+	 *
+	 * @return Tile|null
+	 */
 	public function getTile(int $x, int $y, int $z){
 		$index = ($x << 12) | ($z << 8) | $y;
 		return $this->tileList[$index] ?? null;
 	}
 
+	/**
+	 * @return bool
+	 */
 	public function isLoaded() : bool{
 		return $this->getProvider() === null ? false : $this->getProvider()->isChunkLoaded($this->getX(), $this->getZ());
 	}
 
+	/**
+	 * @param bool $generate
+	 *
+	 * @return bool
+	 */
 	public function load(bool $generate = true) : bool{
 		return $this->getProvider() === null ? false : $this->getProvider()->getChunk($this->getX(), $this->getZ(), true) instanceof Chunk;
 	}
 
+	/**
+	 * Unloads the chunk, closing entities and tiles.
+	 *
+	 * @param bool $save
+	 * @param bool $safe Whether to check if there are still players using this chunk
+	 *
+	 * @return bool
+	 */
 	public function unload(bool $save = true, bool $safe = true) : bool{
 		$level = $this->getProvider();
 		if($level === null){
@@ -447,6 +710,10 @@ class Chunk{
 		return true;
 	}
 
+	/**
+	 * Deserializes tiles and entities from NBT
+	 * TODO: remove this
+	 */
 	public function initChunk(){
 		if($this->getProvider() instanceof LevelProvider and !$this->isInit){
 			$changed = false;
@@ -506,26 +773,49 @@ class Chunk{
 		}
 	}
 
+	/**
+	 * @return string
+	 */
 	public function getBiomeIdArray() : string{
 		return $this->biomeIds;
 	}
 
+	/**
+	 * @return int[]
+	 */
 	public function getHeightMapArray() : array{
 		return $this->heightMap;
 	}
 
+	/**
+	 * @return int[]
+	 */
 	public function getBlockExtraDataArray() : array{
 		return $this->extraData;
 	}
 
+	/**
+	 * @return bool
+	 */
 	public function hasChanged() : bool{
 		return $this->hasChanged;
 	}
 
+	/**
+	 * @param bool $value
+	 */
 	public function setChanged(bool $value = true){
 		$this->hasChanged = $value;
 	}
 
+	/**
+	 * Returns the subchunk at the specified subchunk Y coordinate, or an empty, unmodifiable stub if it does not exist or the coordinate is out of range.
+	 *
+	 * @param int  $y
+	 * @param bool $generateNew Whether to create a new, modifiable subchunk if there is not one in place
+	 *
+	 * @return SubChunk|EmptySubChunk
+	 */
 	public function getSubChunk(int $y, bool $generateNew = false) : SubChunk{
 		if($y < 0 or $y >= $this->height){
 			return $this->emptySubChunk;
@@ -536,6 +826,14 @@ class Chunk{
 		return $this->subChunks[$y];
 	}
 
+	/**
+	 * Sets a subchunk in the chunk index
+	 * @param int           $y
+	 * @param SubChunk|null $subChunk
+	 * @param bool          $allowEmpty Whether to check if the chunk is empty, and if so replace it with an empty stub
+	 *
+	 * @return bool
+	 */
 	public function setSubChunk(int $y, SubChunk $subChunk = null, bool $allowEmpty = false) : bool{
 		if($y < 0 or $y >= $this->height){
 			return false;
@@ -549,10 +847,18 @@ class Chunk{
 		return true;
 	}
 
+	/**
+	 * @return SubChunk[]
+	 */
 	public function getSubChunks() : array{
 		return $this->subChunks;
 	}
 
+	/**
+	 * Returns the Y coordinate of the highest non-empty subchunk in this chunk.
+	 *
+	 * @return int
+	 */
 	public function getHighestSubChunkIndex() : int{
 		for($y = count($this->subChunks) - 1; $y >= 0; --$y){
 			if($this->subChunks[$y] === null or $this->subChunks[$y] instanceof EmptySubChunk){
@@ -565,10 +871,18 @@ class Chunk{
 		return $y;
 	}
 
+	/**
+	 * Returns the count of subchunks that need sending to players
+	 *
+	 * @return int
+	 */
 	public function getSubChunkSendCount() : int{
 		return $this->getHighestSubChunkIndex() + 1;
 	}
 
+	/**
+	 * Disposes of empty subchunks
+	 */
 	public function pruneEmptySubChunks(){
 		foreach($this->subChunks as $y => $subChunk){
 			if($y < 0 or $y >= $this->height){
@@ -585,6 +899,11 @@ class Chunk{
 		}
 	}
 
+	/**
+	 * Serializes the chunk for sending to players
+	 *
+	 * @return string
+	 */
 	public function networkSerialize() : string{
 		$result = "";
 		$subChunkCount = $this->getSubChunkSendCount();
@@ -620,6 +939,12 @@ class Chunk{
 		return $result;
 	}
 
+	/**
+	 * Fast-serializes the chunk for passing between threads
+	 * TODO: tiles and entities
+	 *
+	 * @return string
+	 */
 	public function fastSerialize() : string{
 		$stream = new BinaryStream();
 		$stream->putInt($this->x);
@@ -638,10 +963,17 @@ class Chunk{
 		$stream->put(pack("C*", ...$this->heightMap) .
 			$this->biomeIds .
 			chr(($this->lightPopulated ? 1 << 2 : 0) | ($this->terrainPopulated ? 1 << 1 : 0) | ($this->terrainGenerated ? 1 : 0)));
-		//TODO: tiles and entities
 		return $stream->getBuffer();
 	}
 
+	/**
+	 * Deserializes a fast-serialized chunk
+	 *
+	 * @param string             $data
+	 * @param LevelProvider|null $provider
+	 *
+	 * @return Chunk
+	 */
 	public static function fastDeserialize(string $data, LevelProvider $provider = null){
 		$stream = new BinaryStream();
 		$stream->setBuffer($data);