Burgh Island is at Bigbury on Sea, in Devon, UK.
Agatha Christy wrote a play, and a subsequent book, in which people die, one by one, on the island at Bigbury.
The mystery unfolds as people die, one by one, on an island with a single mansion, separated from the mainland,
The book is now titled "And then there were None". The original title of the book was, believe it or not, "Ten Little Niggers", but times changed, and it was relabeled "And Then There Were None".
I think the best thing at Bigbury is the really old pub, I think associated with, or part of the Pilchard Inn. It is the first notable thing on the island. It is a nice old pub, featured in many movies and TV programs.
The island is in a tidal area which makes it less accessible at high tides, but you may walk to it at low tides.
Later, there was a bit of 4-wheel machinery there, called "The Thing"... a carriage on very long stilt legs, allowing passage to and from the island at high tide.
See The Mousetrap
, or Lovejoy