Sunken ruins are ruins that are partially or totally submerged beneath an ocean, lake, or other body of water. Fictional sunken ruins are often sunken cities, submerged statues, or entire castles now at the mercy of the waves. These structures may be leagues beneath the surface in underwater trenches or sitting amidst the shallow waters of a coast. They offer worldbuilders a chance to expand a fictional history or ancient civilization as well as act as interesting locations to explore in narrative and game worlds. Sunken ruins may be legendary and are frequently the target of treasure hunts. They are home to aquatic civilizations, fish, and leviathans.

Partially Submerged Ruins

Ruins that are only partially submerged, especially those found along a coast or within tidal flats, may be revealed or hidden with the changing of the tides. This can be used to create spaces or chambers which flood, generating tension within narratives or terrain hazards in game worlds. It may even be the case that the entire ruin itself is only revealed during periods of extremely low tides and subject to the gravitational pull of a nearby moon. These types of sunken ruins, as well as ones that rise from the depths, may feature waterfalls cascading down their surfaces.

Fully Submerged Ruins

Fully submerged ruins, such as those that may be resting on the seafloor, are often modeled after the fabled Atlantis (if they aren’t actually Atlantis). While these ruins are entirely inundated, and perhaps home to aquatic creatures and leviathans, air pockets trapped within these structures can provide worldbuilders an opportunity to create spaces where surface-dwellers can survive.

Rising Ruins

Often in fictional worlds, ruins from long ago rise forth from the depths. This may be because of a magic, long dormant mechanisms, a prophecy being fulfilled, or a religious event transpiring.

Fictional sunken ruins are often found along coasts, deep in oceanic trenches, hidden amidst towering kelp forests, or nestled in coral reefs. These interesting locations can act as a backdrop or be interwoven throughout the ruins themselves.

The location of sunken ruins can also depend on the territory of an ancient civilization as well as what type of structure it once was.

Ruins may have become submerged because of gradual erosion and the slow march of time, sudden earthquakes, the creation of a reservoir, the destruction of a dam, or a myriad of other reasons. In fantasy worlds powerful magic, curses, or the gods may have been involved. These events, as well as what purpose the original structure served, can serve as part of a fictional history of a world or minor location. This history may be reflected in the architecture of the structure.