"Roger Hayter" wrote in message
...
I need to fit a small gate to a single post with the gate's free side
over the top of a retaining wall with no (practical or aesthetically
satisfactory) way of fitting a post on the free side. The gate has to
remain fairly robustly shut (resistant to the weight of a small dog) but
simply openable by a human.

I can think of one or two ways to do this but is there a standard way,

Yep, a fixed plate at the hinge end of the gate with a pin thru the plate
and part of the gate that stops it opening unless the pin is raised.

a commercial product,

Havent bothered to look but I'd be surprised if there isnt.

or experience of something that works?
Many thanks for any thoughts.

Even brain farts ?