Bertrand Russell, Mountains and Mountaineering

Russell, in his criticisms of Meinong's metaphysics, and in particular Meinong's theory of non-existence, often uses Meinong's own example of the golden mountain as an impossible object.

There is also an entry under Meinong for golden mountain.

(If you know the original source of Meinong's reference, I'd be very grateful to hear.)