Heretic/E1M6: The Cathedral

This map contains a few secrets, and also requires you to open doors that would otherwise be considered secret in other situations. You start in the northwest corner of the map.

Yellow key
The yellow key is directly behind the starting position, but is on a raised platform. To reach it, make a hard right turn, and go up the steps. Once you reach the window overlooking the cathedral, the platform below the key has lowered to the ground level. Drop directly down to grab the key.

You can now exit the church section through the yellow door.

Green key
If you want an Etheral Crossbow, flip the switch at the bottom-left, and run to the lowered lift at the north-west corner.

Travel to the east edge of the room, and flip the switch to lower the nearby lift. Continue east, collect a bag of holding and silver shield if desired to enter a large room. This room will darken if you try moving between the pillars, but doing so allows you to collect a claw orb. Continue through the doorway.

In the next room is a door in the south-east corner, marked by a misaligned texture. Head into the spiral stairs, and jump across the altar. This allows you to access the graveyard.

There are two things to perform in the graveyard. First, approach the altar on the right to allow access to the green key. Next, open a concealed door marked by a glowing light in the south-west corner of the building. This not only brings you to a switch that raises the stairs to the green door, but to a teleport that brings you near the Tome of Power.

Exit
Go through the green gate, at the south-east exit of the central room. Take the northwest path, until you reach the platform overlooking the central room. Flip the switch to allow access to the exit switch in the north-east corner of the central room. This exit switch lowers the center platform, which you can enter.

Secrets

 * 1) When starting the map, turn around, and open the west alcove.  This reveals gauntlets of the necromancer.
 * 2) After getting the above secret, enter the eastern alcove.  It's empty in single player, aside from a nitrogolem, but you must enter it to claim the secret.
 * 3) Northwest of the darkened room is a small alcove.  Open this to retrieve a map scroll.
 * 4) North of the darkened room is an alcove where you can collect a claw orb.  You may either walk through the wall, or locate a teleport past the green key gate to enter this secret.
 * 5) South of the darkened room, which is opened by a secret door bordered by two hanging skulls. Leads to a shortcut back to start or to a previous room.
 * 6) In the graveyard, look on the west-edge of the building for a misaligned texture.  Open to collect a shadowsphere.
 * 7) Take the north-west exit in the graveyard.  This reveals a teleport which allows you to reach a morph ovum near the beginning.
 * 8) When you flip the switch that allows access to the exit switch, walk off the platform (or at least walk just beyond it.)  This opens a secret door.  The secret door contains a large number of items between the stairs, but the stairs only lead to a closed door.  You can open it by flipping a switch at the southern part of the level, revealing the secret exit.

While not tagged as secret, you can collect the Wings of Wrath by entering the south-west alcove just past the green gate. This lets you collect items at the start of the level.