I understand that the Menai bridge was popular with Spitfire pilots from Rednal, the Clifton suspension bridge received its fair share of AFS pilots from Weston Zoyland and Merryfield and a Hunter flew under Tower Bridge in 1968. I know a chap who flew a Venom under some German bridge in the 1950s...
There's plenty of room under the Severn Bridges to fit a VC10 - but that wouldn't be a good idea!