Quinta da Regaleira is a quinta located near the historic centre of Sintra, Portugal. It is classified as a World Heritage Site by UNESCO within the "Cultural Landscape of Sintra". Along with the other palaces in the area such as the Quinta do Relógio, Pena, Monserrate and Seteais palaces, it is considered one of the principal tourist attractions of Sintra.
The property consists of a Romantic palace and chapel, and a luxurious park that features lakes, grottoes, wells, benches, fountains, and a vast array of exquisite constructions. The palace is also known as "The Palace of Monteiro the Millionaire", which is based on the nickname of its best known former owner, António Augusto Carvalho Monteiro. The palace was designed by the Italian architect Luigi Manini.