Temple of the Four Elements

From the introduction:

The Temple of the Four Elements is a dungeon meant for a party of level 5-7 adventurers. The temple itself is a stronghold composed of 4 separate towers, sealed away within a pocket dimension. Its creator, Cassidy Van Hellker was a mage who wanted to better research the four fundamental elements to unlock their mystical secrets. In doing so she separated the four elements into four towers, each tower then took on the properties of the element stored within them.