Castles are supposed to be intimidating, right? When these imposing structures were built they weren’t intended to be friendly, cheery outposts, much the opposite — they were supposed to tell potential invaders that they were in for a fight and then some. Caernarfon Castle retains this intensity, a huge motte-and-bailey beauty that is often thought to be Edward I’s Constantinople, a stunningly expensive piece of work that still isn’t completed to this day, Caernarfon Castle was held by many different hands over the centuries, but the 21st century sees it under tourist control. It looks particularly fetching when the sun is setting.