Mysterious Islands

Poveglia, a small island near Venice, Italy, is investigated; an exploration of Japan's Battleship Island reveals a troubled history; strange trees are found on the Yemeni island of Socotra; on Indonesia's Flores Island, a skull is found in a cave.

A headless skeleton is discovered on Australia's Beacon Island; near the Marshall Islands, a huge undersea crater is discovered; in Mexico, an island full of dolls reveals a grim history; animal bones are found on an island in the English Channel.

An abandoned Cold War era Russian military base is explored; a stone structure is discovered on the seafloor near Yonaguni Island; a palatial mansion is found on Isla Grande; a turbulent past is unearthed on Italy's volcanic Stromboli Island.

Human remains are unearthed on Daksa island; flying objects are spotted above Maury Island; on Isle of Wight, remains of a previously unknown species of dinosaur is found; strange ritual artifacts are uncovered on Sweden's Bla Jungfrun Island.

Stone artifacts, burial grounds, and temple ruins shed light on an unknown civilization; the discovery of a green light emitting in a dark forest; the remains of a long-lost temple are found; coral rubble is unearthed on Suakin Island.

Coastal erosion exposes skeletal remains; researchers discover a special type of spider; new evidence leads archaeologists to unravel the unsolved mystery of the lost Roanoke settlers; thousands of dead seals confound a wildlife enigma.