Have you ever looked at the differences between the Scouts program that serves youth in the UK? There's quite a few similarities, but there's also some differences. The Brits don't call them "merit badges" for starters, they're "activity badges", and there aren't quite as many of them as there are in BSA.
Nonetheless, the Brits have some badges that are really cool and that, I think, are more adventurous than what the too-timid BSA allows. For example:
Caver
Dragon Boating
Martial Arts
Parascending (I think we would call this "parasailing")
Source: https://w