Wales is often called the "Castle Capital of the World," and while hundreds of castles exist, the most famous were built by King Edward I of England during his conquest of Wales in the late 13th century (1276–1295). This "Iron Ring" of fortifications, which includes Conwy, Caernarfon, Beaumaris, and Harlech, was designed to permanently suppress Welsh resistance. These are now UNESCO World Heritage sites and represent the pinnacle of medieval military architecture. However, many other castles were built by Welsh Princes (like Llywelyn the Great) to defend their own territories, or by Norman Marcher Lords earlier in the 11th and 12th centuries to secure the borderlands. Notable Welsh-built examples include Castell y Bere and Dolbadarn. The sheer density of castles in Wales—over 600 in total—is a physical testament to the centuries of brutal conflict between English monarchs and Welsh leaders, creating a landscape that is today one of the world's premier destinations for historians and tourists alike.