ELKINS PARK, Pa. – The only synagogue ever designed by Frank Lloyd Wright has been designated a National Historic Landmark. Beth Sholom, a soaring glass-and-concrete temple just outside Philadelphia, began welcoming worshippers nearly 50 years ago. On Sunday, the National Park Service recognized it as one of the architect’s greatest achievements. “This is not just a historic site,” William Bolger, regional program manager for the park service, said of the building conceived as a modern Mount Sinai. “It is a living monument to our nation’s culture.” The towering, flat-topped spire is constructed out of concrete, steel, aluminum and glass.