Originally developed as a suburb of San Francisco's Downtown District, West Portal's building boom began in the 1920’s with the opening of the trolley tunnel under Twin Peaks. The neighborhood was named for its proximity to the west entrance of the Twin Peaks Tunnel. At one end is an entrance to the MUNI underground, taking residents directly to Downtown, San Francisco. MUNI is also easily accessible to get to San Francisco State University or Stonestown Shopping Center. Four trolleys (K, L, M, and T) trundle out of the West Portal tunnel at the foot of Twin Peaks, connecting this neighborhood to Market Street as well.