One of station 75's three intact buildings — and already standing open, emptied by whoever got there first.
The Gnoll Armory is one of the three buildings still standing at the centre of Station 75's ruined cavern, alongside the Hobgoblin Repair Shop and the saferoom. It should have been a windfall: the gnolls served as the rail system's security, and their dead lie all over the station with nothing left but broken spears and chewed armour.
Instead Carl sees with dismay that the door is already open. Someone came through before them and got inside, and since every corpse in the cavern has likewise been stripped of its gold, the same visitors probably raided the hobgoblins' stash as well. It is a small, sharp disappointment in a station that otherwise gives them everything they need.
A squat intact building among warehouses and open workshops, its door standing open on a room somebody else has already emptied.
Station 75's weapons store, looted before the party arrived.