Colonia del Sacramento is a city in thwestern Uruguay, by the Rio de la Plata, facing Buenos Aires, Argentina. It is the oldest town in the country and capital of the departament of Colonia. Founded in 1680 by the Portuguese, Colonia was later disputed by the Spanish settled on the opposite bank of the river at Buenos Aires.
The colony kept changing hands from crown to crown due the treaties like the Treaty of Madrid in 1750 and the Treaty of Santo Ildefonso in 1777, until it remained with the Spanish. It then transferred to Portuguese control again and later to the Brazilians after 1816, when the entire eastern bank (Banda Oriental) of Uruguay was seized by the Rio de Janeiro government.
Street plan in the oldest part colonia, built by the Portuguese, contrasting nicely with the wider orthogonal streets in the Spain area.