Noted as one of the finest examples of the City Beautiful movement design in the U.S., the Indiana World War Memorial Plaza Historic District began construction in 1921 in downtown Indianapolis.[118][119] The district, a National Historic Landmark, encompasses several examples of neoclassical architecture, including the American Legion, Central Library, and Birch Bayh Federal Building and United States Courthouse. The district is also home to several sculptures and memorials, Depew Memorial Fountain, and open space, hosting many annual civic events.[119]
After completion of the Soldiers' and Sailors' Monument, an ordinance was passed in 1905 restricting building heights on the traffic circle to 86 ft (26 m) to protect views of the 284 ft (87 m) monument.[120] The ordinance was revised in 1922, permitting buildings to rise to 108 ft (33 m), with an additional 42 ft (13 m) allowable with a series of setbacks.[120] A citywide height restriction ordinance was instituted in 1912, barring structures over 200 ft (61 m).[121] Completed in 1962, the City-County Building was the first skyscraper in the city, surpassing the Soldiers' and Sailors' Monument in height by nearly 100 ft (30 m).[122] A building boom, lasting from 1982 to 1990, saw the construction of six of the city's ten tallest buildings.[123][124] The tallest is Salesforce Tower, completed in 1990 at 811 ft (247 m).[125] Indiana limestone is the signature building material in Indianapolis, widely included in the city's many monuments, churches, academic, government, and civic buildings.[123]