Estonia | France
More ruins than anything else, the castle offers rampart walks, beautiful views of the harbor below, and some local art exhibits.
France
This is Carcassonne's castle and offers the only option to walk the rampart walls - a can't miss experience.
Spain
Sevilla's Alcazar is the oldest royal palace still in use.
Slovenia
Sitting on a cliff overhanging lake Bled, this castle dates from the year 1004, making it the oldest castle in Slovenia. The castle terraces offer amazing panoramic views of the lake, the countryside, and the mountain ranges of the Karavanke and Julian Alps.