Las Arenas, technically a raised beach, was originally a sandy beach with a shoreline. However, sea levels dropped, or this part of Gran Canaria rose, and left the sand stranded high above the sea.
You can see the pale sand at Las Arenas all the way from Puerto de las Nieves on a clear day and it pops in and out of view as you drive the wild west Gc 200 road. That's about as close as most people get as the walking path from the road to the sand is absurdly steep.
A few eccentric hermits live in caves at Las Arenas even though there is no natural water source. Other than that the whole area is wild and pristine. Swimming off the rocks at Punta Gongora is risky because of the strong currents so we don't recommend it.
It's also home to animals and plants that live in other sandy areas of the island but not anywhere else in west Gran Canaria.