Lanquín is a small Q'eqchi' Maya town in Alta Verapaz, set in a hot green valley east of Cobán. It is not polished, and the road in can be slow, but it has one strong reason to exist on a travel map: it is the nearest village base for Semuc Champey, one of Guatemala's best natural sights.
The town itself is simple: a plaza, steep lanes, tuk-tuks, backpacker lodges, and pickup trucks leaving for the pools. That roughness is part of the deal. You come here to swim in limestone terraces, watch bats pour out of Grutas de Lanquín at dusk, and use the village as a launch point for caves, river tubing, and forest walks.
Lanquín works best if you accept its pace. Spend one day on Semuc Champey and the caves, then give yourself an unhurried morning in town before heading back toward Cobán or onward to Flores.