In 2014, Borgring, near Køge, Denmark, was identified as the fifth geometrical Viking Age ring fortress in Denmark, complementing an exclusive group of monuments including Trelleborg. Excavations and surveys in 2016–18 allow a detailed reconstruction of the site and its history. Borgring is a fortification with the same geometry, construction, and location as other Trelleborg-type fortresses, though exhibiting notable differences. Finds, including beads, ornaments, and iron tools, reflect activities and links to other fortress sites. The dating of Borgring is established with reference to wiggle-matched 14C dates.