The smallest island in the world is Bishop Rock, being it follows these specifications and requirements of being an island:
1. An island must be completely detatched from other lands, thus, it must be surrounded by water. Islands cannot be conjoined with other lands, as will qualify them for other land types.
2. An island MUST be inhabited, or formerly inhabited.
The smallest island in the world is Bishop Rock, 46 meters x 16 meters (736 square meters). The land pretrudes from the surface of the water around 4 feet (almost a meter), and has a lighthouse that is 44.2 meters high (approximately 144 feet). The lighthouse was originally intended to be 24 feet shorter (120 feet), but was washed away due to low reinforcement and island height. Bishop Rock is approximately 74/1000 hectares (1 hectare being 10,000 square meters), and is smaller than the Olympic Swimming pool, and a Rood, however, it is larger than a Chinese Mu and the Principality of Sealand (artificial island).
It serves as a border between the Atlantic Ocean and Great Britain. It is also at the westernmost tip of the Isle of Scilly. In 1901 a barque wrecked near Bishop Rock, drowing all her crew.