If you visit Lisbon, Portugal, you'll find St. George's Castle hard to miss. Located on the highest hill in the capital, it can be seen from almost anywhere within the city. It's not surprising the castle is the main historical and tourist site in this beautiful city.

Research has shown that some of the castle may date back to 6th century B.C., when Celtic and Iberian tribes inhabited it. However, the castle came into glory around 2nd century B.C. Today, it is the perfect place to watch the sun rise and set or to stop under one of its many trees for a rest in the shade. There is even a restaurant in the former royal residence if you find yourself tired and hungry after walking through the many courtyards and paths.

Don't be fooled by the calm surrounding the castle now – cannons do remain throughout the walls reminding visitors of the castle's original purpose. While you're there, make sure to take some time to examine these special features!