Lisbon - Monastery of Jerónimos

A UNESCO World Heritage Site is a place (such as a forest, mountain, lake, desert, monument, building, complex, or city) that is listed by the UNESCO as of special cultural or physical significance. The list is maintained by the international World Heritage Programme administered by the UNESCO World Heritage Committee, composed of 21 states parties which are elected by their General Assembly.

The program catalogues, names, and conserves sites of outstanding cultural or natural importance to the common heritage of humanity. Under certain conditions, listed sites can obtain funds from the World Heritage Fund. The programme was founded with the Convention Concerning the Protection of World Cultural and Natural Heritage, which was adopted by the General Conference of UNESCO on November 16, 1972. Since then, 186 states party have ratified the convention.

As of 2011^[update], 936 sites are listed: 725 cultural, 183 natural, and 28 mixed properties, in 153 States Parties. Italy is home to the greatest number of World Heritage Sites to date with 47 sites inscribed on the list. UNESCO references each World Heritage Site with an identification number; but new inscriptions often include previous sites now listed as part of larger descriptions. As a result, the identification numbers exceed 1200 even though there are fewer on the list.

The Monuments of Portugal were constructed throughout the Portuguese territory, and date back to the period of pre-historic settlement of occupation. Subsequently, the region that is today Portugal has been colonized by many civilizations, which have left marks in the territory, constructing markers, defensive structures, homes and places of worship to suit their requirements and means. The formal organization of the Portuguese state resulted in a process to qualify and quantify those structures that have had an intrinsic value to the Portuguese culture. Starting with the Direcção Geral dos Edifícios e Monumentos Nacionais (DGMEN), and later by the Instituto de Gestão do Património Arquitectónico e Arqueológico (IGESPAR), the Portuguese government developed a registry of national monuments that includes a rich heritage of historical monuments throughout the country. This is a compilation of those structures that are designated as National Monuments (Portuguese: Monumentos Nacionais) only.