Even in daylight, walking into the defunct Bush Street Synagogue feels much like entering a haunted house.

Dirt and moss cover the front of the once-elegant, long-neglected building near Japantown. Grass growing on the roof hangs over the front of the two-story structure. Steep, creaky stairs lead into a narrow hallway and a dark, musty sanctuary filled with discarded bicycles, tires and shopping carts. Rusty brown water stains mark the interior walls and ceiling.

Yet the dilapidated building was a highlight of the recent tour of San Francisco Jewish history taken by 40 visitors here for the American Jewish Historical Society's annual conference.

Sue and Felix Warburg, who own San Francisco Jewish Landmarks Tours, led the three-hour bus excursion through the city. The tour headed to the Judah L. Magnes Museum and the East Bay later in the day.

Before visiting the former synagogue, the Warburgs pointed out city institutions created with the help of or named for Jews. They include the San Francisco Zoo, Steinhart Aquarium, Stern Grove, Golden Gate Bridge, San Francisco Chronicle, M.H. de Young Museum and the Holocaust memorial outside the Palace of the Legion of Honor.

As they pointed out the sights, the couple rattled off the names of Jews who helped build the city, many of whom flocked to the area after the Gold Rush of 1849. Sue Warburg, herself, has a stake in that era. Her greatgrandfather was among the Gold Rush trailblazers.

The most renowned San Francisco Jewish pioneer, of course, was Levi Strauss. Born in a Bavarian village, the young entrepreneur arrived by ship in 1853 and within a few years opened a dry-goods business. In 1872, he patented copper rivets for the jeans that made him famous.

Though Strauss is better known, Adolph Sutro is arguably the Jewish pioneer who contributed the most to the city's history. Mount Sutro, Sutro Heights Park and the state-owned Sutro Library still bear his name.

"He was really quite a Renaissance man in many ways," Sue Warburg told the visitors.

Sutro was born in Alsace-Lorraine and immigrated to the city in 1850. He became a millionaire as an engineer in the booming mining business. An interest in botany led him to start buying thousands of acres of sand dunes in the 1880s and finally owning one-twelfth of what is now San Francisco.

"Everybody thought he was totally nuts," said Sue Warburg.

Sutro, however, found a way to tunnel for fresh water underneath the dunes. He planted trees and developed the western side of the city. In 1896, he built the opulent Sutro Baths with its six swimming pools, at the northern tip of what is now Ocean Beach.

San Francisco Jews have also been trailblazers in politics. Now home of one of the state's two Jewish Democratic senators, the city was also the residence of the country's first Jewish congresswoman. Florence Prag Kahn, who grew up in the city, was a Republican member of the House of Representatives from 1924 to 1936.

Jewish presence in the city's history, though, didn't translate into strong religious observance or distinct communities.

"Life here has been assimilated," Sue Warburg said bluntly.

Though some argue that there's never been a Jewish neighborhood in the city, the Warburgs said Jewish communities existed in the outer Richmond district earlier this century and near Japantown in the 1890s.

"Now we have no real Jewish ethnic area in San Francisco," she added.

The former Bush Street Synagogue near the corner of Laguna Street is a remnant of one Jewish area.

The only sign that the structure ever hosted Shabbat services is a small plaque in the lower right corner of the building's front. The Hebrew inscription bears the name of the congregation, Ohabai Shalome, or Lovers of Peace.

Built in 1895, the redwood building survived both the 1906 and 1989 earthquakes. For many years, Felix Warburg said, the structure housed a "more conservative" though still Reform congregation that broke off from Congregation Emanu-El in 1863. Ohabai Shalome disbanded in 1934 and sold its building.

A large, circular sign on the exterior now reads "San Francisco Go Club." Until recently, players of the popular Japanese strategy game had rented a top-floor room for 60 years.

The long-neglected building still maintains a few remnants of its previous charm. The sturdy pews in the sanctuary are original, as are their purple seat cushions filled with horse hair. The acoustics of the sanctuary remain excellent. Though covered with plywood, the stained-glass windows are still intact.

For several years, the Warburgs along with the local arts community have been trying to raise the money to renovate the synagogue and create a performing arts center.

Regardless of the structure's fate, Felix Warburg said one scenario is certain: "The future of the building is not as a synagogue."