Located in the south of the state upon the Tennessee River, Chattanooga is one of the greenest cities in the United States, making it an excellent choice for nature lovers and outdoor enthusiasts. Criss-crossed by electric buses and featuring several well-used riverfront walkways, Chattanooga itself is home to some interesting sights, including the space-age Tennessee Aquarium and the unmissable Hunter Museum of American Art, which houses a wonderful collection and provides spectacular views of the river from its location on the top of a bluff. However, the real allure of Chattanooga lies in exploring its natural bounty, with most of the action centred around Lookout Mountain. Active travellers will relish the hiking and climbing routes available at Rock City, while Ruby Falls - a gorgeous cascade located within Lookout Mountain - is an unforgettable sight.