We found this to be a hidden gem in Lisbon. When you go inside you pay $4 Euro and you are treated to a magnificent tour of Lisbon history. There are Cenotaphs of famous people from Portugal in several places. You can go upstairs and step out on balconies and get great views of the entire area. There is also a museum on the 3rd floor that gives you a look into the first president after the Monarchy was dissolved. this is a must see if you want to learn about the history of the country read more