TV Guide National Geographic Channel Saturday

Bidders vie for an 18th-century flintlock, a four-barrel gun so complex and expensive to produce that only the wealthy could afford one, making such items highly desirable. Sean Rich and his fellow Lords also inspect a piece of Second World War memorabilia possibly used by couriers behind enemy lines, which if authentic could be valued at $18,000

Fuzz Townshend and Tim Shaw lead a team of experts who secretly restore dilapidated classic vehicles for their unsuspecting owners. Here they get their hands on a Mazda MX5 that needs putting back on the road

Off the coast of Sicily, investigators discover traces of a naval battle. Using divers, an underwater robot and a crane, they haul a long-lost battleship relic to the surface. In Terracina, a team of archaeologists dig inside an ancient mountaintop temple, and in Carthage, Tunisia, clues reveal how one deadly rivalry tilted the scales of power in favour of Rome

Archaeologists venture into the Colosseum's ruins, and launch digs across the Empire, to hunt for clues as to how it became the greatest symbol of the Roman Empire. As teams descend into hidden tunnels and unearth long-lost amphitheatres in Tuscany and Britain, they piece together the surprising truth about Rome's iconic arenas

International teams of archaeologists embark on a series of excavations to unravel the secrets of life in the Roman Empire, beginning with a new dig in Pompeii. The team races against the clock to unearth a sacrificial skull, uncover clues from a tomb, examine the mummified body of a curiously wealthy freed slave, and venture into stiflingly narrow tunnels beneath the central bathhouse

The facts about the natural phenomena, which have made headlines as massive sinkholes have appeared at home and abroad, swallowing cars, buildings and, in one case, almost burying a woman alive when she fell down a hole in her garden. This documentary breaks down the science of these terrifying freaks of nature