Rabbi Mortimer J. Cohen was a visionary with chutzpah. In November 1953, on the advice of a mutual acquaintance, he wrote the most famous architect of his day to ask if he would consider designing a suburban Philadelphia synagogue. What was needed, the rabbi informed Frank Lloyd Wright, was "a 'new thing' -- the American spirit wedded to the ancient spirit of Israel." Cohen took the further liberty of enclosing his own sketches.

Wright, then 86 and based at Taliesin West, in Scottsdale, Ariz., had turned down previous requests to build synagogues. But Cohen's invitation to develop a distinctively American architectural idiom for a Jewish house of worship enticed the architect. Six years later -- despite fund-raising woes, the daunting complexity of Wright's design, and flooding from a burst pipe -- Beth Sholom's imposing glass pyramid in Elkins Park, Pa., was dedicated to wide acclaim.

This fall, the Conservative synagogue, designated a National Historic Landmark in 2007, celebrated its 50th anniversary by inaugurating a visitor center and public tours, available three days a week or by appointment. Together, they offer an intriguing look at the congregation, the architecture, and the extraordinary collaboration between Cohen and Wright....

Beth Sholom has always stood apart. The building, unusual in both form and materials, radiates otherworldliness. Symbolizing Mount Sinai, and evoking a vast desert tent, the hexagonal structure towers above the leafy avenue by day. By night, it emits an eerie silvery glow that illuminates the roadway. Most passersby -- until recently, I was among them -- have never seen the synagogue's remarkable interior. The main sanctuary, which holds more than 1,000 worshipers, combines grand architectural gestures with Wright's signature detailing. The beige-carpeted floors slope downward, while the walls of the temple soar dramatically skyward, a dynamic contrast that creates vertigo and seems to obliterate the distinction between heaven and earth.

Wright, who borrowed liberally from his own unbuilt 1926 design for the Steel Cathedral for a Million People, employed the metaphor of the congregation "resting in the very hands of God."... The dominant geometric form of Beth Sholom is repeated triangles. Wright also used motifs from Mayan and Assyrian art and trompe-l'oeil finishes. Beams of aluminum-clad steel, cast aluminum and painted concrete are all pewter-gray. Fiberglass paneling on the interior and corrugated wire glass on the exterior make the temple translucent.

Wright called the sanctuary's chandelier, made of panels of colored Plexiglas and resembling a three-dimensional kite, a "light basket," Emily T. Cooperman, preservation director of the Beth Sholom Synagogue Preservation Foundation, says. He ultimately opted against stained-glass windows. "Let God put His colors on, for He is the great artist," Wright declared. An ingenious interactive display demonstrates the results: Visitors can navigate through 360-degree views of the synagogue's interior and exterior at different times of day and during each of the four seasons....

The relationship between the rabbi and the architect is at the heart of the Beth Sholom story. Wright even put Cohen's name on his architectural drawings, a highly unusual move. Cohen, a sophisticated man who led the congregation for more than four decades, often cajoled and flattered the narcissistic Wright. "I have read of and followed your achievements with amazement," the rabbi writes as he baits the hook. "Here is hosanna, in the highest!" he exclaims in response to Wright's initial designs. "I leave to your greatness my hopes and dreams," he says later.

Wright, for his part, complains -- he is worried about payment, among other things, and reminds Cohen that he has only postponed, not waived, his customary fee. (Just a misunderstanding, the rabbi reassures him.) But Wright also flatters and comforts Cohen. On April 15, 1958, the rabbi laments to the architect: "Our money raising efforts languish. Collections have come to a dead stop. People are losing faith..." Wright responds briskly, "Do cheer up!" and tells him that all will be well.

The building was finally completed. But Wright, who died on April 9, 1959, was not there to see it. For Cohen, the Sept. 20, 1959, dedication must have been a bittersweet occasion. A half-century later, the new visitor center eloquently unearths the human underpinnings of one of Wright's greatest architectural achievements.