Kizlyar Fortress, Military fortress in Kizlyar, Dagestan, Russia.

Kizlyar Fortress is a military stronghold in the Terek River delta built with massive stone walls and strategically positioned bastions. The structure shows how old defensive buildings were designed to protect trade routes and border regions.

The fortress was built in 1735 under Russian control as part of a chain of defenses protecting Russia's southern border. It played an important role in controlling trade routes between Russia and Central Asia.

The fortress's name comes from the Kizlyarka river, at whose mouth it was founded in 1735. Its presence turned the neighbouring settlement into a town at once, and by the mid-18th century a customs house operated there: everyone entering the Russian Empire from the south had to pass through Kizlyar to register. Relatives of mountain rulers were held in the fortress as amanats, hostages guaranteeing their loyalty.

The fortress stood on the right bank where the Kizlyarka leaves the Terek, with three sides facing open ground and two shielded by the river and its branch. Its three gates — north, east and south — were reached over drawbridges on cast-iron chains. Visitors should orient themselves by these sides and gates rather than expecting standing ruins.

In July 1765, Nogai murzas Sokur Adzhi, Roslanbek Karamurzin and Koshkabal led 4,000 Kuban Nogais against Kizlyar and besieged it for a month and a half, reaching the point of storming the walls; the assault was repulsed with heavy losses for the attackers.