Akhtynskaya Fortress (Lezgin Akhtseg-Kyele) is a Russian fortress in Dagestan, located in the village of Akhty in the Akhtynsky District, built in 1839 by General Golovin. It is a historical and architectural monument of federal significance. It is the southernmost fortress on the territory of Russia.

Akhtynskaya Fortress consists of the following structures: fortress walls, soldiers' barracks, an Orthodox church, and a powder magazine.

The fortress has a pentagonal shape with barbette towers at the corners of the bastions. Previously, there was a moat with stone walls 4.57 meters high and 1.06 meters thick. The curtain walls of the fronts consisted of defensive barracks, on top of which an infantry position was arranged to fire on the approaches. The fortress was armed with 11 cannons and 6 Kagorn mortars. The tactical position of the fortress was disadvantageous due to the poor visibility of the terrain near the fortifications because of the relief features.

In 1839, after the suppression of the Kuban uprising by Russian troops, General Yevgeny Golovin’s units marched into the restless Samur Valley, effectively establishing Russian authority along the troops' route. The result of Golovin’s Samur campaign was the subjugation of the Altyparinsky, Dokuzparinsky, and Akhtyparinsky free societies, as well as the Rutul magal. To strengthen the occupied positions in the conquered territories, the Samur District was established with its center in Akhty. The district was administratively part of the Kuban province of the Russian Empire. In Akhty, a fortress was built in forty days, becoming the stronghold of the Russian administration in the Samur Valley. The fortress also served as the residence of the head of the Samur District. Today, the fortress is a historical and architectural monument of federal significance. Geographically, Akhtynskaya Fortress is the southernmost fortress on Russian territory.

In 1848, Imam Shamil’s troops launched the Samur campaign, the main goal of which was to capture Akhty—the center of the Samur District—and establish control over the Samur Valley, which was under Russian administration. During the battles from August 14 to 22, the fortress was besieged and repeatedly assaulted. The mountaineers managed to blow up the powder magazine. The murids occupied almost the entire district, but after energetic measures by General Argutinsky, the fortress garrison was saved, Shamil’s troops suffered a tactical defeat, and retreated to the upper reaches of the Samur Valley, to Avaria.

After the October Revolution, the fortress ceased to function. Later, a winery and a cinder block production facility were established there. During the first 20 years of the Soviet period, the fortress was used as a prison, and after the Great Patriotic War, as an orphanage. In the 1970s, local collective farmers organized the production of paving slabs and mechanisms for wind-up toys in the fortress barracks. Later, a branch of the Derbent Defense Plant "Electrosignal" was opened here, employing 200 people. Production stopped in the 1990s. Currently, the fortress is closed to visitors, but there is no control over compliance with the regime, so the fortress is effectively accessible to everyone. Despite being under state protection, there is no maintenance. Many fortress structures are in a state of disrepair, and cows graze on the site.

Sources:

https://ru.wikipedia.org/wiki/Ахтынская_крепость