Sintra is both a town and a municipality in Portugal, located in the district of Lisbon. The town is a UNESCO World Heritage Site on account of its 19th century Romantic architecture. The town of Sintra refuses to be promoted to City Status, despite being the center of the second most populated municipality of Portugal. Sintra has become a major tourist attraction, with many day-trippers visiting from nearby Lisbon. Attractions include the fabulous Pena Palace (19th c.) and the Castelo dos Mouros (reconstructed 19th c.) with a breath-taking view of the Sintra-Cascais Natural Park, and the summer residence of the kings of Portugal Palacio Nacional de Sintra (largely 15th/16th c.), in the town itself. The Sintra Mountain Range, one of the largest parks in the Lisbon area, (Serra de Sintra) is also a major tourist attraction.