The Hollywood Subway, as it is most commonly known, officially the Belmont Tunnel, was a subway tunnel used by the interurban streetcars (the "Red Cars") of the Pacific Electric Railway. It ran from its northwest entrance in today's Westlake district to the Subway Terminal Building, in the Historic Core, the business and commercial center of Los Angeles from around the 1910s through the 1950s. The Subway Terminal was one of the Pacific Electric Railway’s two main hubs, the other being the Pacific Electric Building at 6th and Main. Numerous lines proceeded from the San Fernando Valley, Glendale, Santa Monica and Hollywood into the tunnel in Westlake and traveled southeast under Crown and Bunker Hill towards the Subway Terminal.