|BUR - 421kHz - Burnham, Buckinghamshire, England|
This, regrettably is the closest I could get to it, being that it lives on seriously padlocked property belonging to the Water Board, or such. No sign of a watery person to try and blag a trip in, either. Maybe next time.
Not exactly sure of the purpose for this beacon; the nearest airport is rinky-dink little modest Heathrow. There are other minor fields fairly nearby, like Booker, and White Waltham.