Marathon: Where to Use the Tunnels Office Key

Similar to ARC Raiders, Marathon has plenty of keys to find on each of its maps. These keys can then be used to open specific doors, leading to rare loot such as higher-tiered guns, barter materials, and even blue shields to help you during combat. However, these doors, just like the keys themselves, are really tricky to find.

One of the keys you'll find in Marathon is the Tunnels Office Key. While this key can be acquired pretty much anywhere in the game, it can only be used on the Perimeter map. We'll discuss exactly where to use it in this guide.

Whether you are trying to find the Tunnels Office Key or are trying to figure out where the door is located that requires it, we have you covered in this guide. Here's everything there is to know about the Tunnels Office Key in Marathon.

How to Find the Tunnels Office Key

Just like any other key in Marathon, the Tunnels Office Key can be found in many different spots. However, it has a better chance to spawn inside of facilities in Perimeter and Dire Marsh. More specifically, these keys are generally found lying on desks, rather than within loot crates.

Out of the many hours I have put into Marathon, I have found the Tunnels Office Key a total of three times. The first time I found it, it was located in North Relay of Perimeter, lying on one of the desks on the second floor. I also found the Tunnels Office Key on a desk in Overgrown on Perimeter and on a desk in Intersection of Dire Marsh.

As you can see, there's no definite way to find the Tunnels Office Key, but your chances of finding it increases significantly if you search inside facilities and loot the top of desks and tables. However, I wouldn't completely write off looting crates for the Tunnels Office Key, as it's possible for them to spawn there too. The chances just seem much lower.

Where to Use the Tunnels Office Key

The Tunnels Office Key can be used on the Perimeter map in Marathon. More specifically, it is used underground in the Tunnels area of the map, south of Station and northwest of South Relay. The good thing is that the map has all locations named, making it easy to ping it and make your way there.

Knowing how to get underground into the Tunnels area isn't very straightforward as there are only a few entrances that lead below the surface. I recommend starting from South Relay and heading northwest, where you will find a pit painted yellow.

It's here where you will find a ladder that leads down into the Tunnels, very close to the door that requires the Tunnels Office Key. Just climb the ladder down, take a left and follow the wall a few feet until you reach a door with an orange keypad. Remember, any door that has an orange key pad, rather than a blue one, requires a key to open.

Don't worry about taking the key out of your inventory to open it. All you have to do is approach the door and interact with it to have the game register that you have it in your backpack, opening the door for you to enter.