This is the 57th in a series of caches that are placed within sight of that Great British establishment, the pub.
The green-roofed building along the sea front was originally developed as the town's bath house in around 1800, although in those days it was a one-storey wooden building with a slate roof. It developed as a sea front hotel from the 1840's, offering salt water baths and a bathing machine for sea bathing.
It was originally built lower than sea level (as the meadows today are still lower than sea level), which was before the sea wall and sea defences were in place. The photo shows the building being lower than the road. Apparently when the tide was high, seawater would break over the road and run through the public bar and out the back door. The old timers sitting with a drink simply raised their feet to allow the water to pass through.
More information on this series here: https://robrohori.wixsite.com/website