Up one of the seven hills of Lisbon, you can find the ruins of the castle of Sao Jorge. Just past some gift shops, sloping past an outdoor urinal (oh how I wish I had taken a picture of it!), and in the sights of a statue of Saint George himself, you can step back in time for a moment and see what once was.
Tagus River Valley Residents

The castle sits on the highest hill in Lisbon, overlooking the city, making it a great position for a military establishment. Prior to the Moors building the castle in the 10th century, archaeological remains have found former residents of the area to include Celts, Phoenicians, Greeks, Carthaginians, Romans, and Germanic tribes such as the Suebi and Visigoths.

The Iberian Peninsula, home to Portugal and Spain, was under Moorish control for a few centuries, up until the Second Crusade. It was during this time that Christian crusaders not only looked East to Jerusalem, but West to Iberia, to earn their favor with the Church. Dubbed the Reconquista (or Reconquest), Christian forces sought to take back the Iberian Peninsula from the Muslim Moors who currently had influence. Well, in 1147, European knights did just that and took control of the castle and the city of Lisbon, setting the fortress up for Christian influences.

Sao Jorge: A Work in Progress
This may come as a surprise, but the castle itself is not the same castle that the crusaders took back in 1147. There have been several additions, removals, and reconstructions over its lifetime, the most modern of which took place starting in the late 1930s. The end result is what we see today.

The views from the castle are simply the best in the city: You can see everything and everywhere, from the houses pressed up at the base of the castle, to the docks along the Tagus River, Lisbon is laid bare before you in all its majestic glory.

In terms of things to do, there is a small cafe and museum, but for the most part, you’ll be walking up and down stairs, across bridges, and along fortified walls to check out empty courtyards, archaeological sites, and through architectural splendor.
It’s a bit pricey, but if you’re into ruins and history, this would be a great way to spend an afternoon in Lisbon!