Bishop Rock is located on the Isles of Scilly in Great Britain. According to The Guinness Book of World Records, Bishop Rock is dubbed the 'smallest island in the world with a building on it.' As you can see from the photo, the building, in this instance, is a lonely-looking lighthouse. Interestingly, the first lighthouse built on Bishop Rock was back in 1847. However, the sea claimed it before they could complete its construction.
Another fun fact for you: the lighthouse in the photo was first lit in 1858, and Bishop Rock sits around 28 miles off the coast of Cornwall. Apparently (weather permitting), various organizations run regular boat trips to the island.