Before you can ask what makes a castle cool, you need to know exactly what makes a castle, a castle. Most were built in the Middle Ages by European ballers in order to defend themselves, their wealth, and really, the continuing of their family lineages. And yes, they were also defending their countries, too.
No one castle should have all that power, but in all honesty, many of them did just what they were intended to do. Over the years, some became pimped out weekend houses or museums, but the real definition is still based in a kind of fortification built for defense—using moats, curtain walls, drawbridges, and elevation on islands, hills, and caves.
No, Hogwarts is not on the list, but yes, Coca-Cola rented out one of these and turned it into Hogwarts for a day. No, a castle is not the same thing as a palace, but yes, we have done a list of those, too.
Imagine yourself on some real luxurious lord or noble type sh*t and take this journey through The 25 Coolest Castles.