Heading southeast of Guachalá, the dirt road climbs through onion fields and páramo grasslands for an hour’s drive until it passes the Las Puntas hills, site of the entrance checkpoint to the vast Reserva Ecológica Cayambe-Coca (daily, 7am–6pm; $10, though this is often overlooked; ID required). Founded in 1970 the reserve protects over 4000 square kilometres of land, from 5790m to just 600m above sea level. This huge range in altitude spans ten ecological zones that harbour a staggering number of plant and animal species, including nine hundred birds (among them the condor, mountain toucan and Andean cock-of-the-rock), and rare mammals, such as the spectacled bear and dwarf deer. Also living within the reserve are Quichua-language speakers at Oyacachi, a village renowned for its hot springs, and the Cofán people, in the far northeast of the reserve at Sinangoé, who offer family-based accommodation for $30–40 per person per day (arrange through the Fundación Sobrevivencia Cofán; wwww.cofan.org).
The reserve’s highest point is the summit of Volcán Cayambe (5790m), Ecuador’s third-highest mountain; just south of the summit is the highest point on the equator, reputed to be the only place on the planet where the latitude and average temperature are both zero degrees. The volcano has a refuge ($17) at about 4700m, reached by a 25-kilometre dirt track leading southeast from Cayambe, with bunks, kitchen facilities, electricity and running water; bring a sleeping bag. The climb from the refuge to the summit (6–7hr) is regarded as more dangerous than either Cotopaxi or Cayambe for its many crevasses, risk of icefall, strong winds and frequent bouts of poor weather, though many agencies in Quito can arrange guides, equipment and transport. Nearer the refuge is an area of crevasses and ice walls often used by climbing schools and agencies for technical training.
There are several other points of access to the Cayambe-Coca reserve, mostly in the Oriente. The road from Papallacta to Baeza and Lago Agrio borders the easily accessed southern and eastern edges of the reserve, and the most common points of entry along this road are from Papallacta, El Chaco and Lumbaquí, 70km west of Lago Agrio.