I've just acquired for twenty round ones in a Carnforth bookshop an engraving showing a Mersey river scene with the following inscription at the bottom of the picture:
"The Ancient Wishing Gate, Liverpool, painted 1797 by S.F. Serres, Esq, Marine Painter to His Majesty George 111."
It depicts the Mersey shoreline with sailing boats anchored and what appears to be a thoroughfare leading down to the edge of the River.
I wondered if it was so-called because it was traditionally the place where Liverpool seamen made a wish for a safe trip before setting sail. But what do I know? Does anyone else know better?