Building 210 was the Avionics Building for the TR-1 spy planes (the successor of the U-2 spy plane) on USAF Alconbury Airfield, it was also known as Magic Mountain or Dragon Mountain depending who you talk to.

In the late 1980s this hardened bunker was built for processing the photos and information collected by the TR-1 Spy planes, the TR-1 was nicknamed “Dragon Lady” which is where the bunkers “Dragon Mountain” name came from.

Most of the bunker is on the ground floor with plant and generators on the basement level it has a large concrete blast cap on top designed to take the impact of an attack.

The building is apparently one of the last bunkers that the US built and is now listed, it opens once a year for tours. These pictures are from 2023, I first visited in 2006 and since then little has changed except now the bunker is much cleaner and better maintained.

The following pictures show the Exterior, Covered entrance tunnel, the decontamination suites for personnel and equipment as well as the rooms where the data would have been processed however no equipment remains except the switchgear giving us a glimpse of the amount of hardware that needed power.