<Li> <P> 99 Kensington High Street entrance on Derry Street . The street - level entrance to the roof gardens . </P> </Li> <P> 99 Kensington High Street entrance on Derry Street . The street - level entrance to the roof gardens . </P> <Li> <P> One of the windows in the walled garden . </P> </Li> <P> One of the windows in the walled garden . </P>

When did the roof gardens in kensington open