Birtvisi is a ruined medieval fortress in Kvemo Kartli, Georgia, nested within limestone cliffs in the Algeti river gorge. It is now within the boundaries of the Tetri-Tsqaro municipality, adjacent to the Algeti National Park.
Birtvisi is essentially a natural rocky fortress of 1 km², secured by walls and towers, the most prominent of which – known as Sheupovari ('Obstinate') – tops the tallest rock in the area. Various accessory structures, an aqueduct included, have also survived.
In written sources, Birtvisi is first mentioned as a possession of the Arab amir of Tiflis of which he was divested by the Georgian nobles Liparit, Duke of Kldekari and Ivane Abazasdze in 1038. In medieval Georgia, Birtvisi entertained a reputation of an impregnable stronghold whose master could control the entire strategic Algeti gorge. The Turco-Mongol amir Timur notably reduced the fortress during one of his invasions of Georgia in 1403. After the partition of the Kingdom of Georgia later in the 15th century, Birtvisi was within the borders of the Kingdom of Kartli and in possession of the princes Baratashvili.
References:Stobi was an ancient town of Paeonia located near Gradsko. It is considered by many to be the most famous archaeological site in North Macedonia. Stobi was built where the Erigon (Crna River) joins the Axios (Vardar), making it strategically important as a center for both trade and warfare.
Stobi developed from a Paeonian settlement established in the Archaic period. It is believed that in 217 BCE, Philip V annexed Paionia during his campaign against the Dardani who had entered Bylazora, the largest Paeonian town.
The city was first mentioned in writing by the historian Livy, in connection with a victory of Philip V of Macedon over the Dardani in 197 BC. In 168 BC, the Romans defeated Perseus and Macedonia was divided into four nominally independent republics. In 148 BC, the four areas of Macedonia were brought together in a unified Roman province. In the reign of Augustus the city grew in size and population.