A walk through SoHo, home to the world’s greatest trove of cast-iron buildings. We consider the district’s original architecture as well as new Landmarks Commission-approved additions.

Reservations required. Tour of the Woolworth Building lobby, closed to the public for more than a decade and now open again. The tour includes a detailed look at the building’s unmatched polychromatic terra-cotta exterior, and an in-depth exploration of the lobby and its wealth of ornament, including hidden corners and staircases — plus a special visit to the mezzanine level for an up-close view of its extraordinary mosaic ceiling.