Complex sentence: An entrance between the train hall and the historic building lead directly to the underground bus terminal, which stretches west for two city blocks along 17th Street until it terminates at an above-ground light rail station.
Split into simpler sentences: An entrance between the train hall and the historic building lead directly to the underground bus terminal. The bus terminal stretches west for two city blocks along 17th Street until it terminates at an above-ground light rail station.