Cañón del Pato, Mountain canyon in Ancash Department, Peru.

Cañón del Pato is a narrow gorge carved by the Rio Santa where two major mountain ranges meet and draw remarkably close together. The vertical rock walls rise steeply on both sides, creating a dramatic passage that barely accommodates a single highway and the river simultaneously.

The road through the canyon follows the route of the former Chimbote–Huallanca railway, which no longer operates. The first stage, from the northern Callejón de Huaylas to the Cañón del Pato hydroelectric station, covers 12.5 km and passes through 35 tunnels, numbered 1 to 35. A second stage of 8 km adds tunnels 37 to 44.

The name does not come from the Spanish word for duck. It refers to the old Patos settlement near Huallanca, a town reached by rail from Chimbote before the line disappeared. The canyon road now follows that former railway route, and the Quechua name Patu Wayq'u echoes the same word.

The road is narrow and winds through tight sections, requiring careful driving and extra time for navigation. Two-way traffic in cramped passages means drivers should remain alert and go slowly through the canyon.

Water from the Rio Santa is channeled through tunnels to power a hydroelectric facility at Huallanca that generates electricity for the region. Most travelers pass through without noticing this concealed infrastructure operating beneath the gorge.