 SCP-291 resembles a small building and structure, a nearly featureless steel box, measuring 10.5 meters by 30.2 meters at the base, and 15 meters tall. On one of the narrow sides, there is a large door, 5 meters wide, that opens upwards, similar to a garage door, composed of metal slats a few inches high each. There is no handle on the exterior of the door, and while closed, all attempts to open it using non-destructive methods have failed. The interior of the door features a lock that can be opened manually to lift the door for a few seconds before an unknown mechanism will force it shut again. At the other end of SCP-291 is a similar opening with a lock and handle on the exterior and interior, allowing the door to be opened from either side. Two small similar hatches, only 1 meter by 1 meter, can be found to the left of both doors, and may be opened from the exterior.