High Quality Content by WIKIPEDIA articles! Euclid Avenue is a street in Cleveland, Ohio. It received nationwide attention from the 1860s to the 1920s for its beauty and wealth, including a string of mansions that came to be known as Millionaire`s Row. There are several theaters, banks, and churches along Euclid, as well as Cleveland`s oldest extant building, the Dunham Tavern. A large reconstruction project, which brought a bus rapid transit line to the street, was completed in 2008.