Playa Grande - Big Beach - is across the estuary from Tamarindo. Despite its proximity it is not easy to reach. You have to go quite a bit inland and then circle back toward the shore, maybe a half hour drive. Much of the area is a national park because leatherback sea turtles use it as a mass nesting area. So not much development and no crowds. Surfers' paradise, Central American style.
As you can see, almost everybody has fun, even the iguana who hangs out by the taco stand.