Carver's poem cannot in fact be located precisely. However, the Lindenhof square is one place where one does have a view of both "the river, and the old part of the city"; it therefore seems justifiable to 'assign' the poem to this location.
Among other things, this poem can be seen as critique of the stereotype according to which happiness and true creativity cannot possibly go hand in hand. At first sight, the poem seems to subscribe to this notion: one can either spend time with the loved one or write poetry ("didn't [...] write because I heard you stirring"). However, the poem in fact shows that it's perfectly possible to savor the happiness of love and to write beautiful poetry – a little later than intended, perhaps, but what does that matter, in the larger scheme of things?