Lambert Castle, originally called Belle Vista, was built in 1892 as the Paterson home of silk mill owner Catholina Lambert on First Watchung Mountain in Garret Mountain Reservation. Designed in the Medieval Revival style with local sandstone and granite, it embodied Lambert’s desire to recreate the castles of Great Britain he remembered from boyhood. The estate later gained an art gallery wing and a seventy-foot observation tower, though the wing was demolished in 1936. After Lambert’s death, the property passed into public ownership and evolved from county offices into a museum and library, preserving a symbol of Paterson’s industrial wealth and local history.