He found that he had this sudden desperate longing for the fuming, smoky streets of Ankh-Morpork, which was always at its best in the spring, when the gummy sheen on the turbid waters of the Ankh River had a special iridescence and the eaves were full of birdsong, or at least birds coughing rhythmically

— The Light Fantastic by Terry Pratchett, Nigel Planer (Discworld, #2)