Cleveland's downtown architecture is diverse. Many of the city's government and civic buildings, including City Hall, the Cuyahoga County Courthouse, the Cleveland Public Library, and Public Auditorium, are clustered around an open mall and share a common neoclassical architecture. Built in the early 20th century, they are the result of the 1903 Group Plan, and constitute one of the most complete examples of City Beautiful design in the United States.[45] The Terminal Tower, dedicated in 1930, was the tallest building in North America outside New York City until 1964 and the tallest in the city until 1991.[46] It is a prototypical Beaux-Arts skyscraper. The two newer skyscrapers on Public Square, Key Tower (currently the tallest building in Ohio) and the 200 Public Square, combine elements of Art Deco architecture with postmodern designs. Another of Cleveland's architectural treasures is The Arcade (sometimes called the Old Arcade), a five-story arcade built in 1890 and renovated in 2001 as a Hyatt Regency Hotel.[47] Cleveland's landmark ecclesiastical architecture includes the historic Old Stone Church in downtown Cleveland and the onion domed St. Theodosius Russian Orthodox Cathedral in Tremont, along with myriad ethnically inspired Roman Catholic churches.[48] Running east from Public Square through University Circle is Euclid Avenue, which was known for its prestige and elegance. In the late 1880s, writer Bayard Taylor described it as "the most beautiful street in the world."[49] Known as "Millionaire's Row", Euclid Avenue was world-renowned as the home of such internationally known names as Rockefeller, Hanna, and Hay.]