pongo
A river canyon or gorge in Peru, especially a narrow, deep one cutting through a ridge or mountain range, carved by an Andean river.
The result is again clearly shown in the topography of the valley wall which becomes bold, inclosing the river in narrow "pongos" or canyons filled with huge bowlders^([sic]) and dangerous rapids.
Where it comes from
From Peruvian Spanish [Term?], thought to be from Quechua puncu/punku or Aymara ponco "door, gate". Semantically, compare puerta.
Adapted from the Wiktionary entry pongo (CC BY-SA 4.0).