The city often cited as having the most castles within its metropolitan or immediate regional area is Naples, Italy, which is famously known as the "City of the Seven Castles." These include historic fortresses like the Castel dell'Ovo, Castel Nuovo (Maschio Angioino), and the hilltop Castel Sant'Elmo. However, if looking at a broader regional capital, Prague is a strong contender, dominated by the Prague Castle complex, which is the largest ancient castle in the world according to the Guinness World Records. From a national perspective, Wales is frequently called the "Castle Capital of the World," boasting over 600 castles, with cities like Cardiff having a castle at their very heart and several others within a short drive. In Germany, the city of Münster is often associated with a high density of manor houses and "water castles" in its surrounding parklands. Ultimately, while Naples holds the specific "Seven Castles" title, the definition of a "castle" (ranging from medieval ruins to palatial residences) can lead to different cities claiming the top spot depending on whether you count ruins, fortified manors, or just primary royal fortresses.