Colonia del Sacramento is a city in southwestern Uruguay, by the Río de la Plata, facing Buenos Aires. Colonia is known for being one of the cities of the Río de la Plata which still keeps the marvelous magic of its history. It is the oldest town in the country and capital of the departamento of Colonia.

Founded in 1680 by the Portugueses, Spain and Portugal fight for it for decades, the city became into a mixture of architectonical styles. The colonial Portuguese style of the buildings, those stone houses with the typical roofs of those times it mixes up with brick houses and the classical flat roofs of the Spanish architecture.

The city is known as Colônia do Sacramento in Portuguese. Today, it has expanded to the east, but its original part still keeps the irregular, terrain-fitting street plan in the oldest part, built by the Portuguese, contrasting with the wider orthogonal calles in the Spanish area. The historical parts of Colonia del Sacramento are named by UNESCO as a World Heritage Site in 1995.