Old hangars
Before the VGS world got biffed I'd regularly stayed over at RAF Topcliffe in the old TANS Navigation classrooms converted into dorms for cadets and instructors, on the side of the C Type overlooking the airfield. No longer really operational after dark in winter it was certainly very eerie.
When the 'pause' was on we only came out every 2nd or 3rd weekend for example to keep the Squadron a going concern.
One weekend I got my dates mixed up and having driven up after work from Manchester I drew the keys to find the whole she bang deserted and very much in the dark. Obviously too fatigued to safely drive back (it was probably 9pm ish) I fired up the flatscreen and watched a film as the oven got to work, and I opened a can.
Now our toilets were located on the opposite side of the hangar so walking across the only lights were from 3 strip lights on all the time way up in the rafters.
As I got literally to the middle a mobile went off somewhere near the end where the Land rovers were parked.
To say it was a bit unnerving would be near the truth - my first thought was some 'travellers' maybe had entered the building to rip it off and it took a few seconds to realise it was an old NOKIA tone, and was inside the DI's box in a Rover. Phew, it was one of ours...
But other than that moment of rabbit nose bum actually always felt very calm in them as opposed to scary, and usually got a good sleep. The clunks and rattles more from the building cooling etc. but I was sure I heard a fire door clunk dully from the opposite corridor when alone but in a warm bed I didn't investigate unless they started opening in sequence towards where I was!