Nab Tower

About

The Nab Tower is a tower originally planned for anti-submarine protection in the English Channel in World War I. It was sunk over the Nab rocks east of the Isle of Wight to replace a lightship after the war, and is a well-known landmark for sailors as it lies off Spithead and marks the deep-water eastern entry into the Solent.

Adapted from Wikipedia (CC BY-SA). Photography via Wikimedia Commons.