Red Lake (Croatian: Crveno jezero) is a karst lake near the city of Imotski, Croatia. It is known for its remarkably high cliffs, reaching over 241 metres above normal water level, and numerous caves. Water drains out of the basin through underground waterways that descend below the level of the lake floor, and so it is sometimes claimed to be of an unknown depth. Signage at the park suggests that from the top of the cliffs to the bottom of the lake is a distance of 582 metres. It is named after the reddish-brown color of the surrounding cliffs.
Like the nearby Blue Lake, it is presumed that the lake emerged when the ceiling of a large cave hall collapsed.