City of Memoria (2017)

An environmental disaster has destroyed all civilization on Earth. Small pockets of humanity have managed to survive by bonding together over scarce resources. Innovative genetic experiments have resulted in some tribes mutating to better adapt to their harsh living conditions. One such tribe of walrus-like humans is rebuilding life in the ruined floating city of Memoria. Hidden by mountains and fixed in place by four massive vines, the entire city rises and falls with the tide.