Poland’s Wawel Cathedral holds the remains of a number of Polish royals as well as some of the country’s most famous religious art, but the real attraction at the massive religious compound is the hanging bundle of bones which are rumored to have belonged to a local dragon.

Hanging next to the cathedral’s entrance are the “real” bones of the Smok Wawelski—the Wawel dragon. They are chained together in a random jumble, hanging high above the main doors. Before the city was founded, the dragon was said to live in a cave under one of Wawel’s rolling hills. He was of the classic maiden-devouring ilk and the local people even had to put out a fresh young woman each month to quell his appetite. According to legend, he was finally killed by a local hero (or a local apprentice depending on the version), who fed Smok a lamb laced with sulfur. This made the beast so thirsty that he drank water from the river until he exploded.

As delightful as it would be if the remains were truly mythological, the bones are actually thought to be fossilized whale bones or mammoth bones. Regardless of their true origin, they have been there for centuries and are credited with magical powers.