Carreg Cennen Castle, Wales
Never trust any list of Europe's best castles that doesn't include at least one entry from Wales. Owing to its tumultuous history of war and rebellion, the Welsh countryside is home to more castles per square mile than anywhere else in the world. Our favorite is Carreg Cennen, the only ruined stronghold to make this list. Actually, we like that Carreg Cennen has been in a ruinous state since 1462. Perched on a lonely limestone hilltop in Brecon Beacons National Park and often shrouded in mist, Carreg Cennen is easily the most evocative castle in the land. And while it may not be quite as popular as the larger Caerphilly Castle, Carreg Cennen will always be first in our hearts. It's open daily between April and October.