The cupola over the RAF College main hall houses the last operational aerial lighthouse in the UK, a legacy from days when RNAS aircraft operated between the east coast and Cranwell (HMS Daedalus).
In the 1920s and 30s, ahead of radio navigation aids, a network of aerial lighthouses had been set up to guide aircraft at night. In the dome is a light, which, in the early days, could be seen as far as thirty miles away as the UK’s most inland lighthouse. The modern light is not so powerful and scans at 15 rpm.
copy and paste from this:
https://www.cranwellian-ian.com/ewEx...%20Copy%29.pdf