If you're interested in diamonds, join a 40-minute free guided tour to see diamond cutters and polishers in action at this workshop. It will prime you on assessing diamonds, then land you in the shop with a chance to own your own sparklers, at a price.
The factory sits on Uilenburg, one of the rectangular islands reclaimed in the 1580s during a sudden influx of Sephardic Jews from Spain and Portugal. In the 1880s Gassan became the first diamond factory to use steam power.