Nosara is really three places: Playa Guiones, where the surf and most of the visitors are; Playa Pelada, smaller and quieter to the north; and the actual Nosara village inland, where Costa Ricans live and the bus stops. Guiones is a long beach break that is as reliable a place to learn to surf as exists in the country, and the town around it has become the yoga capital of Costa Rica.
What makes Nosara unusual is the zoning. Building is set back behind the tree line and street lighting is deliberately minimal, largely to protect nesting turtles, so the beach has no hotel frontage and the nights are properly dark. The Ostional National Wildlife Refuge just north is one of the few places in the world where olive ridley turtles arrive in arribadas — mass nestings of tens of thousands of animals over a few days, usually around the last quarter of the moon between July and December.
The roads in are rough and the town is spread out; most people rent something with clearance, or a quad.