Yam Fortress built
1384 CE.
Shown on the map at 59.377°, 28.595°.
Yam (also Yama or Yamgorod; Russian: Ям) is a fortress and heritage site located on the eastern bank of the Luga river in Kingisepp, Leningrad Oblast, Russia. The fortress was built in 1384 by Ivan Fyodorovich, a boyar (noble) of the Novgorod republic, to protect the republic's western borders. Thanks to it, Yam remained unconquered from the 14th to 15th centuries. The fortress was completely rebuilt after the Novgorod Republic was incorporated into the Grand Principality of Moscow. Following the construction of Ivangorod Fortress, Yam fortress lost its military significance. Between the end of the 16th century and the beginning of the 17th century, Yam fortress was captured twice by the Swedish army, and the fortress was awarded to Sweden in 1612 by the Treaty of Stolbovo. Russians stormed the fortress in 1658 and captured most of it, however the Swedish garrison held out in the Detinets. Subsequently, the Swedish army demolished most of the fortress (except for the Detinets) to re-build it. Construction of a new bastion-type fortress was begun but never finished. In 1703 the fortress was recaptured by the Russians.
Text from the Wikipedia article Yam fortress, licensed CC BY-SA 4.0.