Located at the top of steep California Street , Nob Hill is known for its grand dame hotels, among them the Fairmont , the Mark Hopkins, the Stanford Court and the Huntington. But the hill's well-heeled reputation really stems from what came before the hotels-namely the fabled mansions of the Mother Lode tycoons and the Big Four railroad barons: Mark Hopkins, Charles Crocker, Leland Stanford and "Bonanza Jim" Fair. All but the Flood Mansion , an 1886 brownstone at the very top of the hill that now houses the Pacific-Union Club, were destroyed in the fire following the 1906 earthquake. Huntington Park , with its copy of Rome 's Tartarughe Fountain, is a wonderful place to view the social elite. Just west of the park is neo-gothic Grace Cathedral, modeled after Notre Dame. Enter from the east side and note Ghiberti's bronze doors, which were made from the same mold as those that hang in the Baptistry in Florence . An outstanding men's and boy's choir sings on Thurs. and Sun. Map 2, C5