the Historic District. In spring 2009, luxury high-rise One Park Place opened-up with 346 units. In early 2017 Downtown's largest residential building opened when Market Square Tower's 463 units were completed. Developers have invested more than US$4 billion in the first decade of the 21st century to transform Downtown into an active city center with residential housing, a nightlife scene and new transportation. The Cotswold Project, a $62 million project started in 1998, has helped to rebuild the streets and transform 90 downtown blocks into a pedestrian-friendly environment by adding greenery, trees and public art. January 1, 2004 marked the opening of the "new" Main Street, a plaza with many eateries, bars and nightclubs, which brings many visitors to a newly renovated locale. Phoenicia Specialty Foods opened a downtown grocery store in 2011, located in One Park Place. In June 2019 Dianna Wray of Houstonia wrote that Downtown Houston had an increased amount of pedestrian traffic and residents compared to the post-oil bust 1980s. Office traffic declined during the COVID-19 pandemic in Texas. By 2022 many offices had split shifts to where workers only went to offices for some days of the week. By 2022 activity at hotel and entertainment establishments recovered. Architecture In the 1960s, downtown comprised a modest collection of mid-rise office structures, but has since grown into one of the largest skylines in the United States. In 1960, the central business district had 10 million square feet (930,000 m²) of office space, increasing to about 16 million square feet (1,500,000 m²) in 1970. Downtown Houston was on the threshold of a boom in 1970 with 8.7 million square feet (800,000 m²) of office space planned or under construction and huge projects being launched by real estate developers. The largest proposed development was the 32-block Houston Center. Only a small part of the original proposal was ultimately constructed, however. Other large projects included the Cullen Center, Allen Center, and towers for Shell Oil Company. The surge of skyscrapers mirrored the skyscraper booms in other cities, such as Los Angeles and Dallas. Houston experienced another downtown construction spurt in the 1970s with the energy industry boom. The first major skyscraper to be constructed in Houston was the 50-floor, 218 m (714 ft) One Shell Plaza in 1971. A succession of skyscrapers were built throughout the 1970s, culminating with Houston's tallest skyscraper, the 75-floor, 305 m (1,002 ft) JPMorgan Chase