You can see the natural sea arch known locally as London Bridge from the sea front at Torre Abbey but for the best view the only way is by water. I suggest parking at Meadfoot Beach where it's free and walking the coast path or follow the roads back to Beacon Cove by Living Coasts.
Swim off from the sheltered beach of grey, smoothed pebbles and you will pass beneath the imposing edifice of The Imperial Hotel where a set of private steps lead down to the sea. A little beyond that is the abandoned terrace garden above Peaked Tor Cove where a path zig-zags down from the coast path making this an alternative start point.
Only once around the pointed 'tor' of rock does London Bridge come into view. If you pick a day in late August or early September and start a little before sunrise then on a clear morning the arch is spectacularly backlit by the rising sun, though to get the arch to frame the sun you'd need to be swimming in the midst of winter (maybe not!). The water beneath the arch is 12 to 15 feet deep even on a low tide and bluey-green filling a slot between narrow barnacle covered walls. Whilst above, the arch is made up of leaves of reddish rocks stacked almost on end and it seems improbable that it has not fallen to winter storms.
Beyond the arch a small bay hides a sea cave beneath a towering cliff on top of which perches the Coastwatch Station and the 'castle walls' of some long ruined folly.
From here the coast bears away northward and Shag Rock and Thatcher Rock far beyond at the limit of the bay come into view between smaller rocks that make a maze guarding the entry to Meadfoot Beach.
Either turn into the beach beneath Triangle Rock and the tiered, blue doored beach huts, or, stretch out the moment a little longer by looping around the outside of Shag Rock, where on a receding tide the current whisks along at a breakneck pace. If you dare to swim amongst the barnacled rocks beneath the overhang of the rock then look up at the fossil corals of a 400 million year old sea bed.
And then it's in to the beach where the café is open by 8am most summer days. All in all it's about 1.3 miles.