Chicago's downtown core, named for the elevated CTA rail loop that encircles it. The Loop is where the city announces itself: the grid of streets laid out after the Great Fire of 1871, the skyscrapers in every architectural style from the 1880s to yesterday, and the culture of the Midwest's largest metropolis. During the day it belongs to office workers and tourists; after dark the streets quiet fast.
The city's best architecture is concentrated here. Willis Tower (still Sears Tower to most Chicagoans) offers the highest observation deck in the Americas. The Rookery (1886) and the Sullivan Center show the birth of the modern skyscraper. Millennium Park with its Cloud Gate sculpture and the Jay Pritzker Pavilion is the Loop's outdoor living room. Grant Park stretches south along the lakefront. The Art Institute of Chicago on Michigan Avenue is one of the great art museums in the country.