Nokalakevi Secret Tunnel

Descending through a steeply pitched, bedrock-hewn corridor into the cooler subterranean air reveals one of Western Georgia’s most intriguing architectural remnants. The Nokalakevi Tunnel is a monumental secret passage cut directly into the limestone cliffs of the Egrisi hills, linking the high Citadel of Archaeopolis directly with the edge of the rushing Tekhuri River. Far from a mere architectural feature, this subterranean shaft represents a sophisticated engineering solution designed to resolve a fundamental vulnerability of ancient and medieval fortifications: securing a continuous supply of freshwater during a prolonged military investment.

The Strategic Architecture of Archaeopolis

To understand the scale and engineering of the tunnel, one must examine the geography of the broader Nokalakevi fortress complex. Serving as the capital of the Kingdom of Lazica (Egrisi) between the 4th and 8th centuries, the stronghold occupied a loop of the Tekhuri River, which provided natural cliffside defenses on three sides. However, the sheer elevation that rendered the fortress secure from direct assaults also separated the garrison from the riverbed far below.

To bridge this gap without exposing soldiers to enemy missile fire, local architects quarried a continuous gallery through the solid rock formation. The construction combined raw excavation with finished stone masonry, creating a vaulted, stepped ramp that descends sharply down the northern incline of the citadel hill. The passage is broad enough to permit the rapid movement of personnel, allowing defensive forces to fetch water safely or potentially launch unexpected counter-sorties against forces attempting to clear the river banks.

The Engineering and Subterranean Features

The craftsmanship of the passage reflects the classic traditions of Late Antique and early Byzantine regional fortification architecture found across the South Caucasus. Limestone blocks line parts of the upper vaulting, stabilizing loose soil strata, while the lower sections are carved directly out of the living bedrock. The grade of the steps is remarkably uniform considering the primitive tools used during its creation, demonstrating a advanced understanding of subterranean geometry.

As the passage approaches the base of the cliff, the ambient humidity rises, and the natural light from the upper portal gives way to a cool, dark environment. The exit emerges directly onto a narrow shelf of white limestone right at the water line. This specific terminus allowed defenders to draw water directly from the deepest currents of the Tekhuri River, where the flow remains fast and clear even when seasonal rains muddy the shallower banks downstream.

Historical Role in the Byzantine-Sasanian Wars

During the mid-6th century, the South Caucasus became a central theater of war between the Byzantine Empire and the Sasanian Persian Empire. Known to Western chroniclers like Procopius as Archaeopolis, Nokalakevi was besieged multiple times due to its position commanding the Colchian plain.

Historical accounts of these sieges frequently note the difficulty armies faced when trying to starve out the Lazic garrison. The presence of hidden infrastructure, such as this secure river access, ensured that even when Sasanian forces completely surrounded the landward walls with siege engines and cavalry patrols, the internal population could endure months of isolation. The structural survival of the tunnel through these heavy bombardments and subsequent centuries of abandonment underlines the durability of early medieval Georgian defensive planning.