The Gateway Arch: a landmark in St. Louis, a monument to the westward movement, facing the Mississippi River. Below it is the westbound Sports Museum (called Jefferson National Expansion Memorial).
Cathedral Basilica of Saint Louis: in addition to its magnificent appearance, the amazing Catholic cathedral has tens of thousands of mosaic murals.
City Museum: it's said that it was rebuilt from an old shoe factory. It's a children's paradise and children's entertainment facilities. The most distinctive feature is the slide. It feels like it is built by all kinds of waste products. It has the feeling of a retro old factory. The museum area has a large ten-story slide, and you can choose to slide down from five or ten floors.