Octopolis and Octlantis are two separate non-human underwater settlements built by the gloomy octopuses in Jervis Bay, east Australia. The first settlement, named Octopolis by biologists, was found in 2009. The individual structures in Octopolis consist of burrows around a piece of scrap metal. In 2016, a second settlement was found, named Octlantis, observed over eight days to have ten to fifteen octopuses. Instead of burrows, Octlantis has dens and is built with seashells.
