I have just added this to the map of places to fly your drone at Drone Scene:
Land owner permission not required.
Parking in Tresaith is limited and costs £2 by way of an honesty box.
Head down to the beach, turn left and you can't miss the waterfall.
The originator declared that this location was not inside a Flight Restriction Zone at the time of being flown on 01/06/2021. It remains the responsibility of any pilot to check for any changes before flying at the same location.