Dartmoor: Newbridge.

A while back, I was asked if I knew the location of the bridge that brought MMT to a halt. God, does it not, loves a visual metaphor, and thus the bus, together with attendant retinue, was famously stymied by a narrow crossway, with the whole shebang forced to reverse half a mile and try another route. (The stars in the above illustration represent expletives from les Fabs, who failed to see the funny side.)
Anyway, I was pleased to reply that I did not know the location, as to have that level of trivia at one's fingertips would represent a tragic waste of a life.
Appallingly, however, having since been unable to resist a rummage for the locale, the tragedy rumbles on: it turns out the offending arches belong to Newbridge on the edge of Dartmoor, a 15th century listed structure which is locally famous, being the subject of postcards and the like, as in this detail from one circa 1930s:


It even has its own Wikipedia entry, and though you'll find no mention of MMT, there is a link to the Coach Drivers' Handbook For The Dartmoor Area, which offers warnings of dire consequences to anyone in charge of a large (possibly multi-coloured) charabanc who doesn't carefully plan their route to avoid narrow medieval bridges.
(Readahs can now relive this episode in Beatles history from the comfort of their own hovels, via the medium of finding the bridge on Google Street view, then repeatedly pressing the reverse button whilst hurling profanity and fulmination at the screen.)