"Everybody was calling it a copper cauldron," Sinclair told Live Science. "But I've seen quite a few old wooden ships, and [cauldrons] didn't look anything like that." However, the mysterious ...

They analyzed proteins from 5,000-year-old copper-alloy cauldrons to see what animals people cooked. Blood, milk, and muscle from cattle, goats, or sheep were all preserved in the pots.

A copper dome recovered from the bottom of the ocean may be the remains of a 17th-century primitive submarine known as a diving bell — one of the world's first, and the earliest ever found.