The Quinta da Regaleira Garden is a historic estate located in Sintra, Portugal. It was built in the early 20th century by an wealthy Brazilian businessman named Antonio Augusto Carvalho Monteiro. The garden was designed to be a mystical and enchanting space, filled with hidden grottoes, lakes, fountains, and other features. The garden is known for its intricate and elaborate design, which features elements of Gothic, Renaissance, and Manueline styles, as well as references to alchemy, masonry, and other esoteric symbols.