Archaeologists in Denmark say a sunken Viking ship near Copenhagen is the largest boat of its kind ever discovered—and that’s saying something. Archaeologists analyzed tree rings in its timber to estimate that Viking artisans constructed the cog in the Netherlands around 1410 CE. A 3D elevation map showing the remains of Svælget 2. Credit: Viking Ship Museum“It is extraordinary to have so many parts of the rigging. “The finds show how something as complex as the rigging was solved on the largest cogs,” Uldum added. Credit: Viking Ship MuseumIn the case of the stern (or back) castle, archaeologists identified details of a covered deck that provided shelter and protection for the cog’s crew.