Moynihan Train Hall is one of the most monumental civic projects undertaken in New York City in a generation. More than a century after the construction of the original Penn Station, and almost six decades after its demolition, the completion of the Train Hall realizes a long-held New York dream. The project, championed by the visionary Senator Daniel Patrick Moynihan, expands the existing Penn Station into the Farley Building. The demolition of the original Penn Station helped catalyze the historic preservation movement, and the lessons of that movement guided the creation of Moynihan Train Hall. Rather than treating the Farley Building as a blank slate, the project team developed a modern rail hub that celebrates the historic building. Completing an incredible transformation of a once insular workplace, the design brings in sunlight, emanates a sense of warmth, and integrates artistic elements into a civic space that travelers have not experienced in decades. Its main concourse is situated in the former mail sorting room, a formerly sky-lit space that was shrouded during World War II. Today, a new skylight traverses this concourse—reclaiming the magnificence of the original, sky-lit Penn Station. The new ceiling comprises four catenary vaults, which each contain more than 500 glass and steel panels that form a moiré effect. Three massive, original steel trusses, previously invisible to the postal workers, were uncovered to support the skylight and become a focal point of the design—seamlessly combining a contemporary architectural element with the workmanship of the original structure.