The Río Castellanos flows through the Quebrada de San Lorenzo in Salta, Argentina. The river's character is defined by a dramatic canyon landscape featuring waterfalls and deep, clear pools. A specific trail known as the Quebrada de San Lorenzo - Cajón y Cascadas del Rio Castellanos provides access to these features, but this trail is on private property and requires a certified guide for entry. The guided hike to the river's waterfalls and canyon is an out-and-back route covering approximately 7.3 miles with significant elevation gain, typically taking between 5.5 and 6.5 hours to complete. This indicates that the primary access for experiencing the river is via a demanding hike rather than a traditional paddling put-in. Standard boat ramps, established paddling routes, seasonal water temperatures, water quality, or specific facilities for kayaking or paddle boarding on this stretch of the river are not available. The area is more oriented toward guided hiking and sightseeing of the river's cascades and pools from the surrounding trails.