In between flights from Brazil to Spain I had 8 hours to spend in Lisbon and I wasn't going to spend it all in the airport. I had been to Portugal only once before when I was 5, so it doesn't really count.
From the airport there is a really nice bus that takes you downtown and back for a few euros. We left our luggage at a deposit at the airport and decided to explore my ancestor's country.
We took the bus directly to the Praça do Comércio (Commerce Square), on the margin of the rio Tejo (river Tagus). This place is commonly known as Terreiro do Paço, because it was the location of the Paços da Ribeira, the royal palace of Portugal, home to one of the largest libraries in the world and that burned down after the 1755 earthquake and tsunami. Most documents regarding the discovery of Brazil were lost, as were hundreds of paintings.
After a visit to the square we took a tram to the Mosteiro dos Jerónimos. It is a fantastic monastery built in the 16th century and final resting place to several kings, and most notably to Vasco da Gama, the first to sail from Europe to India, and Luís de Camões, father of the modern Portuguese language.
A short walk from the monastery is the famous Torre de Belém, probably the most famous landmark of Portugal. It was built as a defense tower to protect commerce from the east and Brazil.