Pena National Palace in Portugal is without a doubt the most colorful castle you’ll ever see. The Castle was built in the late 18th century under the direction of King Ferdinand II who obviously wanted something colorful and enlightening to serve as the summer palace for the Portuguese royal family. I can imagine the look on everyone’s face the first time they visited the castle. If you travel to Portugal for a vacation this castle listed as a UNESCO World Heritage Site is probably worth visiting.