Admetus

Admetus is the only hospitable planet within the Salas System in the Elysian Sigma. It's second from the sun, has a single, very large barren moon and an abandoned Orbital Station known as Admetus Abandoned Orbital Station. 
The planet is home to the Admetans, a species of humanoid amphibians who can hold their breath for very long but cannot breathe under water - their their biology does seem to support life in and out of water all the same. It's questionable whether they could survive in an environment where they were not frequently submerged. 
The Admetans appear to be technologically primitive, and they are a hunter/gatherer society, where each settlement is almost too far from the next to make contact. 
Their religion revolves around gods based on animals that are important for their culture, such as the Octupus - the overgod and "creator", the god of hunting - The Shark, the God of the sea - The whale and the god of the land and sky - the bird. 
Their culture doesn't appear to sponsor war, though they appear to have different approaches to this. Some of them are indeed capable of defending themselves, while others seem entirely pacifist. 
The planet has at one point had another humanoid species, that was non-amphibian, and much more technologically advanced than the Admetans. This species granted the Admetans the technology necessary to survive on the planet. The Admetans, as a result, live in houses and Pyramid-Vaults that are made in similar fashion to Insta-Panels. 
The lost city of Admetus appears in the mythology of the Admetans, who believe it's linked to an "ark" which will improve the life quality of the Ademtans for ever. The lost city immediately appears to be an underwater facility of modern standard, likely used for kolto harvest.