Hm... that's strange. There's nothing there!
I have just tried to look for a defnintion of Zawn in
the dictionary and there is nothing there. The term is
common amongst climbers in the British isles.
It describes a coastal feature in which the sea has eroded
an amphitheatre like shape out of a cliff face.
Think fjord but not nearly as deep as no glacier
has been involved in the formation process, only the sea.
Also there need not be a river running
in from the top.
Zawns will often have a cave at the back.
One of the most famous zawns in the UK
is Wen Zawn (which is on the island of Anglesey in North Wales)
and the climb that traverses the lip of the
cave at the back of Wen Zawn is A Dream of White Horses.
I have been informed by Gritchka that the word has Cornish origins.