The Sidney B. Cushing Memorial Amphitheatre, also known as the Cushing Memorial Amphitheatre or simply the Mountain Theatre, is a 4,000-seat open-air venue in Mount Tamalpais State Park, in Marin County, California, United States.
Location: Mount Tamalpais State Park, Marin County, California
Capacity: 4,000
Opened: 1913
Full name: Sidney B. Cushing Memorial Amphitheatre