Lisbon is a great city with many attractions, but for me, the clear highlight was the Monastery of Belém, properly called the Mosteiro dos Jerónimos. This huge building is the classic example of the Manueline style that is so widespread in Portugal and features a huge number of fascinating architectural elements of all kinds. It can take quite a while to visit all parts of the complex (and to find your way through the masses of visitors), including the fantastic cloister and courtyard, and the church with its tombs of many Portuguese royals, as well as of Vasco da Gama and the country's national poet Camoes. A part of the complex is occupied by the Portuguese Naval Museum, which has some pretty good exhibitions and is definitely worth a visit (including the very nice cafeteria at the end). The second part of the WHS, the tower of Belém, is just a short walk away and is probably the most famous landmark of Lisbon. Formerly used as a lighthouse, defensive tower (there used to be a second tower on the opposite shore so that hostile ships could be caught in the crossfire), and prison, it can be reached today via a small wooden walkway and is a nice addition to the monastery as they represent the highlights of Renaissance architecture in Lisbon. The best views of both the monastery and the tower can be enjoyed from the top of the nearby Monument to the Discoveries. Belém is some distance outside the city centre and is quite a long and crowded tram ride away, so the entire visit can easily fill a whole day.