East St. Louis is a city in St. Clair County, Illinois, United States, across the Mississippi River from St. Louis, Missouri, in the Metro-East region of Southern Illinois. Once a bustling industrial center like many cities in the Rust Belt, East St. Louis has been severely affected by loss of jobs due to deindustrialization during the second half of the 20th century. In 1950, East St. Louis was the fourth largest city in Illinois when population peaked at 82,366. As of the 2010 census, the city had a population of 27,006, less than one-third of the 1950 census.
One of the highlights of the city's waterfront is the Gateway Geyser. Located on the grounds of Malcolm W. Martin Memorial Park, the fountain is the second-tallest in the world. Designed to complement the Gateway Arch across the river in St. Louis, it shoots water to a height of 630 feet (190 m), the same height as the Arch.