Badwater Basin is a single-stage Payload map with four checkpoints for BLU team to capture. It is a large basin that enters into an open corridor of buildings. It was the first Payload map added to the game to feature only a single Stage. It was revealed on the third day of the Heavy Update.
Badwater Basin was the second Payload map added to the game.
The Ridge: (also called Above or The Cliffs) This high ground spans from BLU's spawn to the first checkpoint. A popular location to launch kritzes from, particularly for Soldiers and Demomen.
The Tunnel: This long tunnel cuts underneath the cliffs, and BLU must push the cart through it.
Sniper Rocks: A U-shaped rock formation that provides cover for Snipers while allowing them to look directly at BLU's spawn. Engineers sometimes build here.
The Garage: (also The Bunker or The Alcove) A small concrete building sunk into the ground that opens directly onto the checkpoint. RED Engineers build both on top of this building and inside it.
The Lobby: Underneath the roof is a complex of several rooms. BLU frequently prepares for assaults up the stairs to the roof here.
The Roof: The top of the building the overlooks B. Similarly to the ridge on A, whoever controls this controls the checkpoint, so Engineers on RED will attempt to secure this area.
The Front Steps and The Back Steps: The two stairways to The Roof. The front steps approach from the first checkpoint, while the back steps approach from the second checkpoint and the back yard.
The Back Roof: This large expanse of area features excellent cover and several health kits. It is an ideal place for BLU to launch volleys of spam onto the roof.
The Back Yard: (also The Courtyard) This is the large area behind the roof.
The Alcove: This is the open room opposite the checkpoint from the roof.
The Bridge and The Bridge Room: This enclosed bridge cuts across the low checkpoint of the map, forcing BLU to go underneath and face volleys of fire. The room inside is a common site of Engineer nests, owing to its defensibility.
The Side Room: This room provides a path from B onto the bridge. It lets out onto a deck that is popular with BLU Snipers.
The Attic: (also The Loft or The Balcony) A two-story building that BLU cannot easily access without capturing C. The heart of RED's defense while on C. The loft generally refers to the back area of the attic, while the balcony generally refers to the front areas of the attic.
The Side Room
The room on the Bridge
The Final Checkpoint
The Alley: The last chokepoint before the final checkpoint. Both BLU and RED use this area as a base, and the corners are the focus of the fighting during the assault on the final checkpoint.
The Pit: The entire lower level is often called this. This is where most of the action takes place.
The Sniper Hut: (also Sniper Tower) The final Sniper deck for BLU. Demomen and Soldiers often come here as well. Engineers will also occasionally forward-base here.
The Map Room: (also called the Window Room) These two rooms branch off the alley and lead to open windows that overlook the final checkpoint. The windows are frequently utilized by BLU to avoid the second corner of the alley. The room has a big map on its wall, lending it the name "Map Room." The room between the map room and the third checkpoint is commonly called "The Outer Map Room."
Overhangs: (also Garages) Underneath the map room and underneath decking across from the map room are two sheltered areas that face the checkpoint. Almost always the site of Engineer nests.
Spiral: (also Spiral Staircase) A spiral staircase directly connecting the lower part of the checkpoint and the Sniper hut. The entrance on the Sniper hut is elevated, limiting the classes on BLU that can access this area.
Back Yard: This is the area between the Sniper Hut and the Spiral. Small skirmishes often occur here.
Chicken Wire Room: This is the room located between the third checkpoint and the Sniper Hut. RED often tries to flank through this room.