Regent Street Quadrant, Westminster, London, late 19th century.

Regent Street Quadrant, Westminster, London, late 19th century. This rounded section of street is known as the Quadrant was originally planned to become a square, with a public building at its center, but in the end it was turned into a place of fashionable shops. John Nash tried to match the famed rue de Rivoli with the Quadran. As this famous street used glass covered arcades, the Quadrant has a covered section along the sides of the street. The Quadrant continues with the round theme used in other areas of the street, and employs the same neoclassical architecture as the rest of the street. (Photo by Museum of London/Heritage Images/Getty Images)