Sintra is a town close to Lisbon and is an important historical heritage site. It has many Romantic architectural monuments which placed Sintra on the UNESCO World Heritage sites list. Sintra has a population of nearly 400.000 inhabitants. The most popular attractions of Sintra are the Sintra Mountains, the Sintra-Cascais Nature Park the mediaeval Castelo dos Mouros, the Pena National Palace and the Sintra National Palace.