Final Doom/MAP24: Quarry

Quarry is a simple level, with all necessary steps required for the map being completed in one area.

Walkthrough
Your first step is to reach the large area in southwest corner of the map. You will have to had west (fighting through monsters as necessary), and turning south. If you are low on health, you probably want to detour to the northwest chamber for a health pack.

In the center area, head to the southeast corridor, and reach the teleporter at the end. This brings you to the blue key. With the blue key, you can head to the exit (killing the Revenant inside).

The only other notable feature in the map is the invulnerability in the east chamber.

Secrets
All the secrets are found in the large area near the exit.
 * 1) In the southwest staircase, there's a section that's darker than the rest.  Hit the north wall to reveal assorted goods (including green armor and double shotgun).
 * 2) In the above secret, use the north wall to reveal a lift (that counts as a secret when used).  It is a vantage point behind a fake wall.
 * 3) In the south-east corridor, there is a fake wall on the south between the two metal markers.  It contains a radiation suit.