Perched on the end of the headland above Porthcurno, this massive boulder once famously rocked back and forth on its own natural pivot with only the slightest pressure; its name supposedly derives from the Cornish verb 'log', meaning ‘to rock’, used to denote the motion of a drunken man. It's been a tourist attraction since the 18th century, but the path out to it involves traversing narrow cliff paths and sheer drops, so it's better appreciated from a distance.
The rock is also associated with an infamous episode of drunken tomfoolery. In 1871 a young naval lieutenant by the name of Hugh Goldsmith (the nephew of the Restoration playwright Oliver Goldsmith) commandeered his crew and knocked the rock off its perch, apparently in an attempt to show the physical prowess of the British Navy. Unfortunately, the locals were so incensed, Goldsmith was forced to restore the rock to its original position under threat of his naval commission – a task that required the efforts of 60 men, winches borrowed from Devonport Dockyard and a total cost of £130 8s 6d (a copy of the bill can be seen in the Logan Rock Inn).
Sadly, Goldsmith’s efforts were in vain: the Logan Rock never rocked again.