Ubajara is a city in Ceará, most famed for the nearby national park.
The caves are accessible by cable car (Tuesday - Sunday, 9 AM - 2:30 PM, R$ 8 round trip) or by a 3-4 hour walk. Because of the ridiculous operating hours for the cable car (assuming that you want to return by it), the walk must be started before 10 AM.
As of December 5, 2017, the cable car is not running. It is said to be undergoing major maintenance, which will probably last until July, 2018. The prices have gone up, it is R$ 35 to go to the Mirante Gameleira, and R$ 60 to go to the waterfall Cafundó.