A small box map with a suspended cage above a lava pit. Three ledges circle the lava pit. You spawn on the middle ledge and can fall or jump to the ledge below. To reach the upper ledge will require a rocket jump into the darkness above. Falling into the lava pit, which is a very common thing to do, will place you inside the cage. There is no escape from the cage except for death.
Bots have no real issue.
The map feels and plays like a quick experiment. For people with very little else to do with their time.
Update: You can escape from the cage by rocket jumping up to a hidden teleporter. Thanks to Cricket for the correction!