market st really is san francisco's "main street", running in a straight line all the way from the ferry building at the embarcadero to the castro and continuing into the hills... it's a transportation mainline, with the muni metro subway running underground and the f-market streetcar line running on the surface... it's also the main commercial strip for the "upper market" neighborhoods including duboce triangle, with many small stores and restaurants, especially along the section between church and castro sts