From publisher blurb:
Deep within a dead marsh full of sunken ruins and danger, the Hydra makes it's lair!
Lair of the Hydra is a printable battemap compatible with any RPG game. It can be used as a standalone gameboard, or combined with any same-scale tileset.
Lair of the Hydra is a day & night set, comprising of 2 30x30 battlemaps. The day version features a gloomy marsh filled with Greek ruins and a large cave for a Hydra. A night the swamp is filled with mist, and braziers provide some light.