Barrie lived on the top floor of Adelphi Terrace House, which is at the river end of Robert Street, off the Strand. When I last visited, his flat had been turned into a set of NHS offices. Type "Adelphi Terrace London" into Google Earth and you can see the flat roof where he used to watch Zeppelin attacks during WW1! As far as I know, Barrie had no particular relationship with Kensington Gardens in the latter part of his life. He used to visit it regularly with his dog Porthos (and later Luath) when living at 133 Gloucester Road between 1897 and 1902, and then more frequently when he lived at Leinster Corner (aka 100 Bayswater Road), which he sold following his divorce in 1909 and moved to the 3rd floor of Adelphi Terrace House (formerly the Caledonian Hotel). On 24 June 1917 he moved to the top floor, with its huge inglenook (there are many photos of the flat in the database), which is where he remained more or less until his death. Btw, to the best of my knowledge Barrie never lived in Wigmore Street.