Guarda is a city and a municipality in the District of Guarda and the capital of the Beiras e Serra da Estrela sub-region in central Portugal. The population in 2021 was 40,126, in an area of 712.10 square kilometres (274.94 sq mi) with 31,224 inhabitants in the city proper in 2006. Founded by King Sancho I in 1199, Guarda is the city located at the highest altitude in Portugal and one of the most important cities in the Portuguese region of Beira Alta. Serra da Estrela, the highest mountain range in continental Portugal, is partially located in the district. The city is served by national and international trains on the Beira Alta and Baixa railway lines. The present mayor is Sérgio Costa, as an independent. The municipal holiday is November 27.