Must see monument when you’re in Lisbon also because of the beautiful area to walk around.
The tower was built between 1514 and 1520. The Portuguese left this place to discover the world.
You can get in but the place is very small so normally you have a long queue to go inside the tower. In case better if you go early in the morning, even tho the outside of the tower gives it best in the sunset!
Price to get in is 6 euros.