The famous volcanic-crater lake of Laguna Quilotoa is a gasp-inducing sight. A lookout on the precipitous crater rim offers stunning views of the mirror-green lake 400m below and the snowcapped peaks of Cotopaxi and Iliniza Sur in the distance. When you ask the locals how deep it is, they inevitably say it has no bottom, which seems entirely plausible given its awesomeness (the geologists say 250m).
Fit walkers can hike the crater rim trail in about six hours; another path leads down to the water on a zig-zagging trail. At the bottom, you can camp (free), head out in a canoe or kayak (per hour $2.50 per person ) and stay the night in a rustic lodge. The hike down takes about half an hour and over twice that to return (you can ride a donkey back up for $10). Guides for hikes further afield cost about $25 per day – one excellent option is the hike past the Laguna to the nearby village of Chugchilán. The alkaline lake water is not potable.