#LookUpNY Answer Day 74: No. 172 Duane Street is a unique example of a historic cast iron façade set in front of a modern secondary façade (a 1990s alteration). Cast iron was the material of choice for a significant number of building facades in TriBeCa and SoHo, in part because it allowed for pre-fabricated, build-able parts that mimicked elaborate stone carvings for a fraction of the price.