Nebraska is a state in the central United States and is part of the Midwest. It borders South Dakota to the north, Iowa and Missouri to the east, Kansas to the south, and Colorado and Wyoming to the west. The capital is Lincoln, the largest city is Omaha. Typical for Nebraska is its agricultural economy, which is dominated by the production of corn, beef and soybeans. The state is also known for its vast prairie and sand hill landscapes. Nebraska tourist attractions include Chimney Rock National Historic Site, a prominent rock near Bayard, and Scotts Bluff National Monument, an important stop for pioneers on the Oregon Trail. In Omaha, visitors will find the Henry Doorly Zoo and the Durham Museum, both known for their impressive displays and exhibits. Also of interest is the Strategic Air Command & Aerospace Museum in Ashland, which is dedicated to the history of aviation and aerospace.