Remains of a bygone era, mysterious rock formations and vast underwater caves. See what five of the strangest dives have on offer

Click here for Part I of World's Strangest Dives

1

One of the Seven Wonders of the Ancient World

In 1994 French archaeologist discovered remains of the lighthouse of Alexandria, which was the main landmark of the city when it was built around 290 BC. At that time the 137m lighthouse was the second largest building on Earth, after the Great Pyramid of Giza and became known as the last of the Seven Wonders of the Ancient World. It was destroyed during earthquakes in the 14th century.

There are several dive sites in the eastern harbour and although a lot of artefacts have been lifted and are displayed in museum, the site still bears thousands of amphorae, well-preserved columns and parts of the ancient city walls, statues and. Diving the harbour area is very interesting but the poor visibility of 5-10m or even less can be off-putting.

2 A converted nuclear missile silo

The silo near Abilene, Texas is 38.7m (127 feet) and slowly flooded with crystal-clear groundwater after it was decommissioned. The site is not open to the general public but local dive centres offer guided trips.

3 Mysterious rock formations

Off the coast of Yonaguni Island, the westernmost island of Japan lies what has been claimed to be the world’s oldest building. Ever since the 1986 discovery of the Yonaguni Monument by dive tour operator Kihachiro Aratake, the site has attracted controversy. Researchers argue over whether the rock formations are manmade or natural. Some believe the pyramid-like structure is part of an ancient city that sank 5000 years ago, others claim the tectonic activity in the area and underwater eddies could have shaped the site. The truth is, no one really knows. But whichever theory future evidence will support, the dive is an eerie experience and a great spot to encounter great hammerheads in winter.

4 Australia's Nullarbor plain



Australia’s vast Nullarbor plain is scattered with limestone caves and tunnels. The Weebuddie cave is the deepest cave of the plain and one of the largest underwater caves in the world. Diving here is a surreal experience. With a visibility of 150m (500 feet), the water is so clear it is barely visible and divers seem to be flying through the cave system.

5 Track Down Anacondas in the Amazon

A few documentary filmmakers have been brave enough to enter the murky waters of the Amazon to dive with the world's largest snake. Although no evidence supports the man-eating image of the animal, the size of a fully grown anaconda alone is intimidating and frightening enough for most people to take a pass on this encounter.