Yes, your wallet will take somewhat of a hit if you’re traveling across the pond. Still, a number of cultural institutions let you in for free every day, including the National Gallery, home to more than 2,300 paintings from the 1250s-1900s. Among the masterpieces are works by Monet, Rembrandt, da Vinci, and van Gogh. Also available gratis are 10-minute talks that deliver more insight on specific paintings, held almost daily. The only fees would be for special temporary exhibits.