India, Oct. 24 -- There's an old army tank sitting on a sandy sea floor off the coast of Aqaba, in southern Jordan, with colorful fish darting around its tracks. It may sound like a video game level, but it is real. According to the official Wrecks of Aqaba photobook, a joint 2020 publication from Aqaba's tourism directorate, Aqaba Marine Park, and a Jordanian marine conservation society, a retired M42 "Duster" anti-aircraft gun was sunk in September 1999 to serve as an artificial reef. The booklet claims that it is the second most famous diving site in Aqaba. Today, divers and snorkelers still come to visit it.

The vehicle is an American-built, 40 mm self-propelled anti-aircraft gun. It first served in the Royal Jordanian Army. In Septe...