It is located in the Great Masurian Lakes system, on the side route from Lake Mikołajskie to Lake Nidzkie. The first wooden lock was built here in 1879. It was erected on an artificial ditch between Lake Guzianka Mała and Lake Bełdany. In 1899–1901, a concrete structure replaced the wooden one. The original manual drive was replaced by an electric one after the war. The filling takes up to 10 minutes whereas the entire lock operation –– 20 minutes. Above the upstream gate there is a road bridge founded on steel girders that connects Ruciane-Nida with Wejsuny. The lock in Guzianka is the most exploited lock in Poland. Nearly 15,000 vessels go through it a year. A new lock –– Guzianka II –– has been operating since 2020.
