The eastern border of the Land of Lightning was no easy path.
A massive canyon stretched across heaven and earth, as if cleaved apart by the axe of a colossal god. It guarded the throat leading into the heartland—Thundercloud Canyon.
On both sides of the canyon stood sheer black cliffs, sharp as blades and hundreds of meters high. Not a blade of grass grew upon them, and beneath the year-round cold, damp mist, they appeared sinister and terrifying.
A colossal fortress, built upon the natural stronghold entirely from dark thunder-patterned stone, crouched like a ferocious beast at the canyon's narrowest entrance.
The fortress was built against the mountainside, layered upon layered, covered with arrow slits, log-and-boulder chutes, and enormous ballistae that gleamed with cold light. Several towering obelisks stood at its summit, their surfaces carved with intricate thunder patterns. Fine arcs of electricity faintly danced across them.
The canyon's middle section had been carved with countless platforms and caves, packed as densely as a honeycomb. Figures moved within them, bows and crossbows drawn, kunai in hand, as icy killing intent filled the damp air. An invisible, crushing pressure blanketed the entire canyon, as though some violent force slumbered deep beneath the earth, poised but not yet unleashed.
Konoha's army halted like a green tide upon a relatively open stony bank several miles from the canyon fortress. No order to make camp was issued. Every gaze remained fixed on the canyon's savage entrance and the densely packed Cloud Shinobi lining the fortress walls as if facing a great enemy.
"What a natural barrier!" The Nara Clan patriarch stared ahead, his brow tightly furrowed. "They have every advantage of terrain, and their defenses are complete. More troublesome still..." He sensed the faint yet heart-pounding oppression in the air. "This canyon itself seems