Panzerlachs, Stone fortification in Vyborg, Russia

Panzerlachs is a stone fortification on the northern coast of Vyborg with thick walls positioned to protect ships entering the harbor. The structure shows typical features of a Renaissance bastion with geometric ramparts, bastions, and heavy defensive walls.

Built in 1579–1580 as the strongest point of the Horn Fortress, the bastion guarded the right flank of the fortification whose outline resembled an animal's horns. Its casemate in the left flank, 10 m high with a 3.5 m outer wall at the base, held artillery on three internal tiers and the roof. Catherine II had it repaired, and a new powder magazine was added in 1782. The other Horn Fortress works were demolished in the 1860s, but Panzerlachs was kept.

The name Panzerlachs comes from Swedish panzer, pantsar (armour) and Finnish lahti (bay), meaning "armour bay". The bastion gave its name to the surrounding Vyborg district, also called Panzerlachs. Since 2013 the former powder magazine has housed an exhibition on the city's archaeology, and since 2018 the casemate in the left flank is open to visitors.

The site is best reached on foot from the old town and sits close to other historic sites along the water. Wearing comfortable shoes is recommended since access to the walls involves uneven ground, and visits are more enjoyable in fair weather.

The name is not German for armour and salmon: it joins Swedish panzer (armour) with Finnish lahti (bay), after the inlet it guarded. The six embrasures in three tiers were cut to fire along the south-eastern curtain wall, and the 10 m casemate in the left flank has a 3.5 m wall at its base.