Chicago the skyscraper era, which would then be followed by many other cities around the world. Today, Chicago's skyline is among the world's tallest and densest. Some of the United States' tallest towers are located in Chicago; Willis Tower (formerly Sears Tower) is the second tallest building in the Western Hemisphere after One World Trade Center, and Trump International Hotel and Tower is the third tallest in the country. The Loop's historic buildings include the Chicago Board of Trade Building, the Fine Arts Building, 35 East Wacker, and the Chicago Building, 860-880 Lake Shore Drive Apartments by Mies van der Rohe.
Metropolitan Tower (Chicago) White, the Metropolitan Tower was named the Straus Building when completed in 1924. Though it was the first building in Chicago with 30 or more floors, it was never officially designated Chicago's tallest building since the Chicago Temple Building, also completed in 1924, is taller by but has seven fewer floors. The Straus Building and the Chicago Temple Building were the first to take advantage of the 1923 zoning ordinance; before then, no building in Chicago could be taller than . The Metropolitan Tower was at one time called the Continental National Insurance Company Building (later Continental Center I). From