From Landmarks Association of St. Louis:
The Plaza Square Apartments Historic District was listed in the National Register of Historic Places on July 12, 2007. Located between 15th, Olive, 17th and Chestnut Streets in downtown St. Louis, the district includes St. John the Apostle & Evangelist Catholic Church from 1860 and Centenary Methodist Church from 1870 as well as the signature high-rise apartments completed in 1961. The Plaza Square apartment complex, the cornerstone accomplishment of the city’s first Urban Renewal project, was designed by the newly formed Hellmuth, Obata & Kassabaum architectural firm in collaboration with Harris Armstrong—an acclaimed leader of the Modern Movement in the Midwest. Evenly divided into two different configurations with a total of 1,090 apartments, the six buildings utilized native limestone, brick, concrete and colorful enameled metal panels (most now painted tan) to create a sleek contemporary aesthetic enhanced by balconies, landscaped grounds and underground parking
Although the "skyscraper home in a garden" initially attracted urbanites of all ages, Plaza Square soon experienced increasing vacancy rates. In 1965, Building # 60 at the southeast corner of 17th and Olive Streets was sold to Bethesda General Hospital which converted it into the Town House retirement community. Now dubbed BLU CitySpaces by a new owner, Building #60 is being converted to condominiums utilizing historic rehab tax credits. Thanks to the National Register nomination prepared by Landmarks Association for that developer, the other five buildings (which have been subjected to repeated foreclosures) are also prime candidates for reinvestment.