The Río Tranquilo is a water body located in the Aysen del General Carlos Ibanez del Campo Region of Chilean Patagonia. It flows into the immense Lago General Carrera, near the village of Puerto Río Tranquilo, which serves as the primary access point and base for paddling activities. The most prominent and recommended paddling route from here is a kayak tour to the Marble Caves, known locally as the Capilla de Mármol (Marble Chapel), Catedral de Mármol (Marble Cathedral), and Caverna de Mármol (Marble Cave). These tours typically launch from the Río Tranquilo Cruise Port, often at dawn, and involve paddling through the crystal-clear waters of the lake to explore these iconic geological formations. The overall character of the experience is defined by spectacular landscapes and the unique opportunity to paddle amidst intricate marble walls sculpted by the water. The village of Puerto Río Tranquilo sees a significant influx of tourists starting each November, indicating the austral spring and summer as the primary season for these activities. Guided tours provide a full safety briefing and kayak instruction prior to departure, and comfortable transfers to the launch point are commonly arranged. The water is described as crystal-clear, contributing to the aesthetic appeal of the marble formations. The area is clearly established as a major destination for organized kayak tours focused on the Marble Caves of Lago General Carrera.