One weekend when it's pleasant going to jail

Holloway Prison and Wormwood Scrubs will be taking part in this weekend's London Open Garden Squares event.

Across the capital floating gardens, roof gardens, allotments and private squares will be among the venues open to the public.

The event, now in its sixth year, features 173 sites this year, including 19 new ones. Highlights include barges at Tower Bridge that can only be reached along a bridge of planks and roof gardens on the School of Oriental and African Studies in Bloomsbury and on the Ismaili Centre in South Kensington

The most popular venues are likely to be the beautiful squares of Kensington, Chelsea and Pimlico - normally only accessible to residents living around them - and Westminster Abbey.

Some sites can only be visited if booked in advance and some charge an entry fee.