MAP01/03: The Catwalk (Master Levels)

The Catwalk is a map that is part of the Master Levels for Doom II. It was designed by Christen David "Chris" Klie, and is contained in the file CATWALK.WAD.

Walkthrough

 * Letters in italics refer to marked spots on the map. Sector numbers in boldface are secrets which count toward the end-of-level tally.

Secrets

 * 1) While inside the exit room, shoot at the middle of the east wall to open access to a hidden area. (sector 227) Inside, you will find twelve armor bonuses, three medikits, a soul sphere, a box of bullets, two shell boxes, a backpack, and a switch near the center. Triggering this switch opens a door in the northeast of this area, allowing access to 15 energy cells.
 * 2) While inside the exit room, shoot at the middle of the west wall to open access to a hidden area. (sector 251) Inside, you will find two sets of four shotgun shells, a berserk pack in front of a switch, and a switch nearby a pillar blocking access to an energy cell pack. Flipping the switch behind the berserk pack enables access to the cell pack, as well as a hallway accessed from the center of the area ending in a switch. Pressing this switch lowers a pedestal with a megasphere on it in the southeast of the area. Pushing the switch near the pillar blocking access to the cell pack opens access to a BFG9000, as well as a doorway in the northwest leading to another switch near the center of the area.  Activating this last switch opens the nearby wall, revealing five shotgun guys and four rocket launchers, and also unlocks access to the megasphere.

Current records
The records for the original map on the Doomed Speed Demos Archive are:

Trivia
In the PC version, the "catwalk" bridge to the exit lowers as the player dashes across it, lowering into a nukage pool with no way to escape, but in the PlayStation version of Final Doom, the bridge does not lower into the nukage, and two teleporters are on either side of it.