Whipsiderry beach is adjacent to Porth beach and can be accessed at low tide from Porth but otherwise there is a stairway in the cliff. Unfortunately due to dangerous rock falls and contentious development above Whipsiderry, the stairway access to the beach has been closed. If you do gain access to the beach by walking either from Watergate Bay or Porth be very wary of more potential deadly rock falls. Also, check the tides carefully so as not to get cut off.
