Avenida da Liberdade is a boulevard in central Lisbon, Portugal, and is considered among the most expensive streets in Europe. Originating in the Passeio Público, an 18th-century park built for the Portuguese nobility, the avenue was built in 1879, when the former park was turned into a major boulevard, marking the northward expansion of the city during the 19th century. The Avenida is also home to numerous embassies and diplomatic missions.