Goose Castle (below) is part of the island gardens around 4 Folly Bridge, and like the entire building is somewhat dilapidated and exuberantly castellated. This photo was taken after the goslings had been hatched for a few days and they had stripped all edible vegetation from their courtyard garden, revealing the paving stones; a nice touch. The buddleia and paint tins give the garden a worked in feel, and the Campanula, Erigeron and Alder in the side wall is a nice touch, and complements the river location very well.
However, there are issues. That wall is too high for goslings, the bulk of the planting is non edible, and the garden lacks both shade and (ironically) water.
The addition of an entrance/exit ramp, a small sheltering roof over the nest, and the some low containers (perhaps paint trays?) some containing water and others loosely planted with dandelions, soft grasses and of course goosegrass would both provide goslings with a tasty snack and not damage the essential garden-nature of a storage area appropriated by wildlife.
Goose Castle may be viewed by looking straight down over this bridge parapet, but for this year at least the geese have flown.