You can’t go to Costa Rica and not see monkeys. Those little Outbreak monkeys are everywhere, and I’m sure even if you don’t see Howler monkeys you probably hear them.
We were lucky and saw all four species of monkey on our trip: Spider, Capuchin (which I call Cappuccino), Squirrel and Howler. Outside our suite in Dominical it was like Monkey TV every morning and later afternoon, we’d lay in the hammock and the entire troupe would navigate through the trees to the banana tree near the pool deck. Good stuff.