I can't figure out why I like these structures but one day I'll visit them all. The first is a series of pre-radar listening devices or acoustic mirrors in Dungeness.
Second is the sea forts at the Thames Estuary, Red Sands.
And lastly is the abandoned Bromhill Lido in Ipswich one of many which can be found on the incredibly beautiful 28 days later site- a real archive of forgotten and decrepit architectural treasures.