The Flodden Wall in Edinburgh, Scotland was built back in the 16th century to keep out any pesky English invaders. Even though the invasion never happened, this 24-foot-tall barrier did a pretty good job of protecting the city from all sorts of shenanigans. Nowadays, you can still spot some remnants of this ancient wall scattered around the city, blending in with the newer buildings like they're playing hide and seek. So next time you're strolling through Edinburgh, keep an eye out for these sneaky bits of history peeking out from the past!