Coroico itself is small — a single plaza, a church, a few crooked streets — and most of what you come for is in the surrounding cloudforest. But the town has a real sense of place: terraces overlooking enormous green valleys, hummingbirds in every garden, a mestizo and Afro-Bolivian population, and a relaxed pace that comes as a sharp relief after the altitude and busyness of La Paz.
Walk up to the Mirador El Calvario at sunset, watch a service at the cathedral on the main plaza, and take a coca-leaf or coffee tour out in the surrounding valleys. The town itself can be exhausted in half a day. For the real attractions see day_trips.