Poveglia, a small island near Venice, Italy, is investigated; Japan's Battleship Island.

Near the Marshall Islands, a huge undersea crater is discovered.

A stone structure is discovered on the seafloor near Yonaguni Island.

On Isle of Wight, remains of a previously unknown species of dinosaur is found.

Some signs of an unknown civilization appears; a green light emerges; remains of a temple are found.

Coastal erosion exposes skeletal remains. Researchers discover a special type of spider.