The road from Puyo to Macas passes the Parque Nacional Sangay. The park gets its name from the presence of the Sangay volcano. This is considered one of the most active volcanoes in the world. Smoke and ash clouds are almost constantly thrown into the air and the earth trembles. Unfortunately, the top of the Sangay is almost always shrouded in clouds. The Sangay is not the only active volcano within the park. The Tungurahua (5 023 mt) also spews lava and ash into the atmosphere with great regularity. A third volcano within the park is the dormant Altar (5,319 mt).

The park stretches from the 800 meter rainforests in the east to the sometimes snow-capped peaks of the 5,400 meter high Sangay. The main ecosystems in the park are rainforests and cloud forests. A few notable residents are the spectacled bear, the mountain tapir and the ocelot.

The park is largely inaccessible due to the nature of the vegetation and the lack of roads. To reach the camp site at the foot of the volcano Sangay, you have to trek through the jungle for three days. The area around the Sangay is one of the wettest areas in Ecuador. Expeditions in this park are very rewarding, but only for those who love hardship. Climbing the Sangay is difficult due to the lack of facilities and requires thorough preparation. Increased activity of the volcano – no matter how carefully prepared an ascent is – can make the trek impossible.