At 4031 sq km, Reserva Ecológica Cayambe-Coca spreads across four provinces, including the Oriente, and includes alpine tundra and rainforest. Volcán Reventador (3562m) and Cayambe (5790m) sit within its bounds. On a clear day, the (alternative) road north from Cayambe to Ibarra, which passes through the village of Olmedo, provides excellent views. Volcán Cayambe is Ecuador’s third-highest peak and, at 4600m on the south side, the highest point in the world through which the equator passes.
The entrance to the park is 32km from Cayambe. A convenient entrance point is the village of Oyacachi.
To climb this extinct volcano, get in touch with a tour agency in Quito that specializes in mountaineering. There is a mountain refuge ($20 per person), but you need a 4WD to reach it. The seven-hour climb is more difficult than the more frequently ascended Cotopaxi. Two-day and one-night guided climbs cost around $240 and include transportation, equipment (plus some rudimentary glacier training), meals and a night in the refuge.
You can also hike parts of the reserve from the Termas Papallacta, which is located near the entrance to the park and owns 200 hectares of land there. Termas Papallacta (02-256-8989) offers four different guided tours ($6 to $15 per person), the most ambitious of which is seven to eight hours and reaches 4100-plus meters above sea level with views of the Antisana, Cayambe, Choza Longos and Antisanilla mountains and Sumaco volcano. You can use the hot springs as a guest for $22.
Most Tena-bound buses from Quito's Terminal Terreste Cumandá will stop in Papallacta ($2.50, 2 hours).