Archaeologists excavating a high ridge in the Fergana Valley have unearthed the ruins of a Sogdian military citadel dating to the 6th century CE. The site, named Kala-i-Surkh, served as a strategic outpost protecting the northern Silk Road routes. Excavations within the central keep revealed a rare archive of military ledgers written on silk fragments and birch bark, detailing the garrison's rations and defensive treaties with neighboring Turkic tribes.
The fortress architecture shows a unique blend of Central Asian mudbrick techniques and Sassanid-inspired defensive bastions. Among the artifacts recovered were silver coins from the reign of Khosrow I and ornate bone carvings depicting hunting scenes. Researchers believe the site was abandoned following the Arab conquests, leaving the administrative records remarkably preserved in the arid, high-altitude environment.