St Peter's Pool is a fantastic swimming spot, a natural lido in the rocks with large areas of flat slab for sunbathing between swims. Follow the narrow road out towards Delimara Lighthouse until you are just past the power station chimney (about 1.5km from the main road), and you'll see a low building on the left with 'St Peter's Pool' signposted on it.
A rough track leads down to a small parking area – if you meet a car coming the other way it'll be a face-off over who'll back up. Don't leave valuables in your car.