Castle is a type of fortified structure to defend against enemies during war. Castles first started developing in Europe around 10th century. It was first built in France and UK and continued to be built for several hundred years. These castles have played an important role in economic and warfare in the UK, they were symbol of strength. Use of castles for defense purposes has rapidly decreased in the modern era. There are hundreds of castles in the UK. Here are some famous Castles of the UK.