Fidra, the leftmost island above houses a lighthouse and can be landed on in calm weather. There is a landing stage on the east side of the island. However, there is also a small pebble beach on the southern side than can be used by kayaks.
The lighthouse was completed in 1885. It's now pretty much a bird reserve, with a webcam operated by the Scottish Seabird Centre.
The island is said to be the inspiration behind Robert Louis Stevenson's 'Treasure Island'. It's easy to forget that Edinburgh is half an hour's drive from here !