The Gateway Arch, also known as the Gateway to the West, is an integral part of the Jefferson National Expansion Memorial and the iconic image of St. Louis, Missouri. It was constructed as a monument to the westward expansion of the United States. It was designed by Finnish-American architect Eero Saarinen and structural engineer Hannskarl Bandel in 1947. It is 630 feet (192 m) wide at its base and stands 630 feet (192 m) tall, making it the tallest monument in the United States. Construction started on February 12, 1963, and ended on October 28, 1965. The monument opened to the public on July 10, 1967.

The Old Courthouse was a combination federal and state courthouse in St. Louis, Missouri that was Missouri's tallest habitable building from 1864 to 1894 and now is part of the Jefferson National Expansion Memorial. It was designed by the firm of Lavielle and Morton, which also designed the early buildings at Jefferson Barracks as well as the Old Cathedral. In 1839 ground was broken on a courthouse designed by Henry Singleton with four wings including an east wing that comprised the original courthouse and a three-story cupola dome at the center.

One Metropolitan Square, also called Met Square, is an impressive skyscraper in Saint Louis. It was built in 1989. The structure stands 181 meters tall, featuring 42 floors and green roofs, and it is still the tallest office building in the city. It was designed by architects Hellmuth, Obata & Kassabaum.

The Wainwright Building is a 10-story red-brick landmark office building at 709 Chestnut Street in downtown St. Louis, Missouri. Built in 1890-91 and designed by Dankmar Adler and Louis Sullivan, it was among the first skyscrapers in the world. It was named for local financier Ellis Wainwright. The ornamentation for the building is adopted from Notre-Dame de Reims in France. It is described as "a highly influential prototype of the modern office building" by the National Register of Historic Places.

Thomas F. Eagleton Courthouse is a modern skyscraper in Saint Louis, built in 2000. The structure has a height of 170 meters and 29 storeys. It is the vastest single courthouse in the U.S. with a surface of nearly 90,000 square meters. The building design pursues a classical tripartite scheme. It was designed by architects Hellmuth, Obata & Kassabaum.

Saint Louis City Hall is a large stone building erected between 1890 and 1904. It follows the design model of the City Hall in Paris. The inscription "City Hall" can be found above doors at almost all its entrances. The main feature of the building's interior is an impressive white marble rotunda.

Saint Louis Public Library (The Central Library) is one of the most significant buildings from the early twentieth century in the city. It was designed by architect Cass Gilbert in 1912. The structure houses a vast collection of books in various fields of study. The Library regularly hosts organized events such as authors' readings, live music concerts and others.

Saint Louis Union Station was built in 1894 and is a great Romanesque-style structure. Once it was a busy train terminal. It was renovated as one of the most popular attractions of Saint Louis. Under one roof you can find restaurants, a hotel, shops, a lake and other interesting forms of entertainments.