The Sima de las Cotorras is a dramatic 160m-wide sinkhole that punches 140m down into the earth into a crater thick with rainforest. At sunrise, a green cloud of screeching parrots spirals out for the day, trickling back before dusk. With binoculars you can see a series of red pre-Hispanic rock paintings that decorate one side of the cliff face, and you can also hike or rappel (M$700) down into the hole. For serious bird-watchers this is an essential stop.
Lodging is available (the spacious six-person, two-room ³¦²¹²ú²¹Ã±²¹²õ are well worth the extra cost), and there is a good restaurant serving scrumptious tamales and handmade tortillas.
From the last stop in Ocozocoautla (Coita), located on Hwy 190 right at the signed turnoff for the Sima, take a taxi (around M$320, 50 minutes). Three daily Piedra Parada colectivos (M$14) also leave from this stop, but let you off 4km before the Sima. Driving from Tuxtla, it’s reasonably well signed all the way. Go all the way through Ocozocoautla, turning right at the minibus terminal (there's a blue turnoff sign here, but it's not visible coming from this direction), go 3.5km north, then 12km on a good dirt road.