Queen Elizabeth II may have unseated Queen Victoria as the longest-reigning British monarch several years ago, but Victoria still holds one record as yet unchallenged by her great-granddaughter (or any other royal family member, as far as we know). In 2015, a pair of Queen Victoria’s underwear from her later years, specially tailored and embroidered with her initials, fetched about $16,000 at auction—making it the most expensive pair of undies ever sold.

And that’s not even the weirdest artifact Mental Floss host Justin Dodd is covering on this episode of The List Show. It’s all about the most expensive items in different categories, from classics like books and paintings to oddities like beetles, human hair, and kidney stones.

Press play below to find out who passed that precious kidney stone and why someone decided to shell out $25,000 for it.

For more fascinating videos, subscribe to the Mental Floss YouTube channel here.