The Turtle God is a turtle-like structure in the sea that lies below the Skyhold, which contained a piece of Karpath's Map. It is unknown what the turtle's purpose is, though it may have been a submarine, an idol worshipped by Um Bongo's people, or a hiding place for the map piece.
Inside the Turtle[]
Although the turtle looks like a turtle from above, inside is a very different story. It's mossy, dirty, and leaking water from the outside. Some TV screens are broken, along with cobwebs and some chests around the area. Inside one of the chests, a piece of Karpath's Map was found. There was a hint to the location hidden inside TV's in Skyhold, the famous quote of "It's turtles all the way down!".