The kids will sleep soundly after playing by the water at Praia de Caneliñas. Look for little critters like crabs and snails, dip a toe in the water or toss a beach ball around!
You'll have no end of sightseeing choices when in Spain. Praia de Caneliñas is an ideal place to begin here, but there are plenty of other fine spots to explore. Cape Finisterre, Ezaro Waterfall, and Mount Pindo are not far from the stretch of coastline and will round out your day nicely.