Bruntingthorpe is 3000m (9943 feet). It is unlicensed and is used mainly by the motor industry as a proving ground plus the likes of Top Gear. They do offer long-term Aircraft storage and I also remember an ex-Air Frog 747 being flown in there a few years ago for destruction testing. In the wake of Pan Am/Lockerbie the CAA were investigating ways of making cargo containers stronger and the oldgirl was blown up to test the efficiency of new materials in withstanding small explosions.