The John M. Mossman Lock Collection represents one of the most complete anthologies of bank and vault locks in the world, with more than 370 locks, keys and tools dating from 4,000 BC to the 20th century. Many of the examples are unique, made-to-order locks that were not produced in commercial quantities and nearly every lock has protected millions in money and securities.

The collection is held on the second floor balcony of the General Society of Mechanics and Tradesmen, which also has a soaring library and beautiful staircases. The building first served as a technical school in 1899, and still serves professional tradespeople to this day.