This picture shows the Devon Seaside town of Dawlish.
The picture was taken along the banks of the local river, Dawlish Waters, and shows a pair of the black swans that Dawlish is famous for. Although the location is marked quite accurately, if you look in the Street View image it is on the opposite side of the river to the position the photographer stood to take the picture. There seems to be some sort of festival going on when the picture was taken – at least I assume that is why there are coloured lights strung across the water.
The exact date is not marked on the slide and therefore is unknown, but probably it is in the 1960s or 70s by the look of the fashions.
River Date Picture Taken: