This antique shop in Principe Real claims to have the world’s largest collection of tiles, which is saying something in Portugal. Solar typically works directly with property owners and construction agencies to source their inventory, and as required by Portuguese laws, every tile here is registered with the government. (Tile stealing is a major problem in Portugal, and other sellers can’t always confirm provenance and guarantee authenticity.) The bottomless stock includes single tiles from the 19th century that go for less than 10 Euros all the up to entire panels from the 17th century that fetch thousands. (The rarer the tiles, the less likely Solar will sell them to foreign clients; they aim to keep the most important of their collection in Portugal.) The family-run business is in its third generation, and has maintained its store on Rua Dom Pedro V since it opened in 1956, making it the oldest standing tile seller in the city.