Uncle John’s ancestral homeland might just be Scotland. Check out the recently discovered Drum castle toilet.

Toilets were developed around the world, independently, thousands of years ago, but archaeologists keep finding older and older prototypes in Scotland. One of the oldest was found by archaeologists in the 1850s at Skara Brae, an ancient settlement on Mainland, the largest of the Orkney Islands off the coast of Scotland. Several stone huts among the ruins contained drains that extended outside their walls. Historians believe that the huts, which date back to 3,000 BC, were one of the first, if not the first, indoor bathrooms on Earth.

And this year, archaeologists working to preserve Drum Castle near Aberdeen discovered two “secret chambers” within its walls that date back to the 13th century. One of them contained a guarderobe—a medieval commode—complete with a wooden seat. In those days, a throne like this one would have been considered cutting-edge and truly worthy of a nobleman, or somebody who could sit in an actual throne (the castle served as the “seat” for the Chief of Clan Irvine). Back then, indoor plumbing was still rudimentary by today’s standards and few people in the region had access to latrines.

And here’s the best part. The toilet was hidden by a construction addition from the 1800s—bookshelves.