Caverns Area 1 is the location of the original Mars Base. While all research has been moved to the newer structures, this aging facility still serves as the primary material transfer point between Area 2 and Site 3.

Your mission is to destroy the hell portal. You'll start out coming down in the elevator, and the door will open. Ahead you will see some armor shards and a 15 health pack. As you grab them, you'll here laughing. 12 spiders are on their way - the easiest place to take care of them is by going back into the elevator and shooting them as they try to come in.

Don't bother with the bay door ahead and to the right, its locked, just head around to the right behind the elevator and go up the stairs. Kill the imp on the catwalk. Proceed to the end of the catwalk. 2 wraiths will spawn behind you, kill them. If you grab the ammo belt on the crate, 4 more will spawn. Easy pickings, since they come one at a time.

Turn the corner, go through the door, and through the next door as well. Kill the imp that spawns. Grab the two plasma canisters and top off your health at the emergency medical station (it has 82). Turn right, go through the door, and go behind the desk to pickup the BFG cell. Two more wraiths will come through the door soon (you can hear them). If you look at the screen behind the desk, it has an easter egg referring to "Gibson Goldstein", the last names of the owners of the website shacknews.com.

Go around the desk and open the next door. You'll see a chaingun soldier here. Kill him, and proceed down the hall. 4 wraiths will spawn as you reach the t-junction. Kill them, turn left (right is a dead end), pick up the shells, and go through the door, and the next one after that.

Go straight, and as you head to the room with the stairs, an archvile will spawn. Kill him, turn around kill the imp that spawns by the door. Back on the other side near where the archvile was is a wraith. Kill him, and grab the shells and adrenaline at the top of the stairs (near the red lights). There's a 30 health pack near the archvile spawn point as well. Go back through the door you came through and kill the two chaingunners. Grab the ammo. Go back into the room you just came from and go out the door on the opposite side of the room.

Here, one imp will attack from the platform while 9 spiders spawn below. Kill them all, head up the platform, grab he two clips, the armor, and go back down the stairs. Use the emergency medical station if you need to (32 available). Go out the door to the right of the medical station. You will get a new objective: activate the service lift to reach the lower levels of the Caverns.

Walk forward, and you will see the elevator shaft to your right heading down into the caverns, but no elevator. Stay right and walk along the catwalk. You will see a panel to extend the service ladder. Use it, and climb the ladder. Walk across the top of the building and you will see some scaffolding . Two cacodemons will spawn, one behind you and one ahead. Kill them, and jump the scaffolding. Turn right and go through the window into the office.

Turn left and you will see a computer console to unlock the cargo lift controls. Use it, and turn around. Go up the stairs and grab the armor shards and the 15 health pack. Go back down, turn left and go through the door. You'll hear some footsteps, but don't worry about that. Go straight and use the console to raise the lift. Go down to level 1 and turn right, You'll hear the classic music that indicates something horrible will happen. Just grab the cells, turn around, go down the stairs and go straight. Grab the rockets and armor shards. Then 10 spiders will spawn off the your right (as you face away from the wall) and near the lift. Kill them, and turn left and go through the door.

As you walk out, you'll recognize the area. Turn left, and call the lift to station. While you wait, 3 imps and a hell knight will spawn. By the time you finish killing them, the lift will arrive, and you will have completed your objective. Next objective: destroy the Hellgate.

Use the panel on the lift to lower it. Don't jump off, the tracks are electrified. As you come down into the lower caverns area, there will be one chaingun soldier on the catwalks shooting at you. If you have a soulcube ready, save it and just use the plasma gun or rockets (if you have a lot). As soon as you jump off the elevator and walk a few feet, the spawning will begin. The most immediate danger is the hell knight off to the right, but the most dangerous overall is the archvile up on the catwalk. Kill the archvile first, then worry about the rest. If you're quick with the archvile, the only other demons are the hellknight and an imp. When the hellnkight dies, a cacodemon will spawn, so be ready for that. Walk to the back of the area and use the panel to open the access hatch, then climb the ladder right next to it to get up to the first level.

A wraith will spawn off to the left. Shotgun him, and and walk to the left. Behind the crates are a BFG cell and some shells. Walk back out and go into the door. An imp will jump at your from the right and a wraith will run at you from ahead of you. Kill both. Off to the right, there is an emergency health station with 32 health. Use it if you need it. Go around to the lift and go up to level 2.

An imp will attack from the dark area off to the right. A spider will spawn. After both are dead, another imp will spawn at the opposite end of the level. Kill him. Near where he spawned is a door back out. (Don't bother with the other door yet, its locked). Go out, kill the two cacodemons. Turn right, go around the corner, climb up the ladder and go through the door. Kill the wraith that's waiting. Grab the pistol and the bullets. Get ready for a long climb down.

Turn right, climb down the ladder. Keep going down as long as you can. You'll run out of ladders and have to jump across some moving platforms to get down. Don't jump too far, since you'll take damage. Climb down the last ladder and use the panel to extend the access ladder (so you have a way to get back up.) Off to the left you'll notice some cells behind the pipe. Jump over the pipe, grab the cells and two 15 health packs. Then crouch, turn right and go under the pipe to an area with the scientist. Grab the shotgun, the shells and the keycard. Time to go back up.

Climb back to the top. As you go back outside, there are 5 cacodemons waiting. First a wave of three, then a wave of two, after the first three are dead. Climb back down the ladder and go back into level two. Kill the wraith. Use the keycard to go through the locked door. Kill the 3 spiders. Grab Robert Cody's PDA on the table, and the clip off to the left. There's also some armor shards on the other side of the table. Go through the next door (back outside) and kill the two imps and three wraiths as you make your way along the catwalk. Go through the next door.

Be careful here: sections of the catwalk fall out, dropping you into the lava. The sides alternate, so start off staying to the right of the catwalk. The move left, then right. Turn the corner, kill the wraith, grab the 30 health. Stay of the left side for the rest of the catwalk after the corner. Grab the rockets and 15 health, then kill the imp and three chaingun soldiers up ahead (rockets aren't a bad way to go). Move into the next room and open the bay door.

Walk in and walk straight to the back of the area (ahead). Kill the imp. Pick up the 2 plasma canisters, 3 clip, 15 med pack, 5 machine guns, 50 armor and adrenaline. Get ready for a battle. Step out near the ladder/panel. 2 chaingun soldiers will appear near the bay door. As soon as you kill them, 5 cacodemons will spawn, in twos (the last one by itself). Kill them, and walk over to the ladder/panel. Ignore the panel for now, it just resets the crane if you mess it up. Climb the ladder.

At the top, use to console to turn it right (until the console says "105"), and then extend the crane all the way (the controls on the left - use the up arrow). Then walk out of the cabin and climb the ladder on the other side up to the top. Walk down the crane until you reach the end (stay to the right), and jump down onto the palette. Jump down again onto the catwalk. Kill the imp near the pipes. A cacodemon will spawn. Kill him, and grab the 2 plasma cells and armor shards inside the pipes if you need them. If you need health badly, there's a 15 health pack on top of the pipes. You can use the crates at the end of the catwalk to jump on top.

Walk down the catwalk and turn the corner. Go through the door. Turn left quickly and kill the imp as he jumps out from the dark corner. Grab the grenades on the console on the other side of the office and go through the next door.

Big fight in here. Go down the hallway until you reach the room with the bay doors. Use the panel to open up the door, and the light will go out. 3 imps and 2 wraiths will spawn. Kill them all, and 2 chaingun soldiers will spawn in the hallway. Kill them as well, and save the soulcube if you can. After everything is dead, you can grab the ammo from the soldiers as well as the shotgun shells and ammo belt. When you're ready (arm the soulcube), call the lift. It will come up with a hellknight in it. Kill him and go down in the lift.

Walk out of the lift. On your right, you'll see some exploding barrels. If you get over them (or shoot them) you can pick up the grenades and clip on the other side. Go down the stairs. Behind the crates is 60 health (2 30 health packs). Keep walking around and an archvile will spawn right near an explosive barrel. Shoot the barrel and then finish him off. He'll spawn an imp back by the elevator, so kill him too. Proceed along the walkway. To your left, a wraith will spawn. Kill him, and turn the corner. There will be another alcove off to your left with an imp in it. Kill him and grab the armor shards in the alcove. Go through the door.

3 cacodemons will spawn along with a chaingun soldier. The best way to handle it is to back up to the door you just came through after they spawn and take down the cacodemons, then walk back out and finish off the chaingunner with rockets/plasma. Cross the bridge and go up the stairs and through the door.

Pick up the 2 plasma canisters, 2 BFG cells, clip and 50 armor and open up the lift that will take you to Caverns Area 2.