Gulper lagoon is a river, flowing downhill and ending in a small pond of still water. There are large trees over the river, with up to four gulpers dangling from their branches. The lagoon is littered with human bones, but it is unknown if they are victims of the gulpers or the Great War.
A shack with a tinker's workbench is at the bottom of the nearby cavern. Strangler vines have grown to create a ramp to easily climb down to it.
Gulper lagoon appears only in Fallout 76.