According to legend King Charles the Second, who ruled Great Britain for twenty five years after the restoration of the monarchy in 1660, was told, when the astronomer royal Sir John Flamsteed complained about the ravens, that the safety of the kingdom was threatened if the birds ever left the Tower of London. King Charles then decreed that there should always be at least six ravens there to prevent the Tower – and the kingdom – falling down. History does not record what Flamsteed thought of this decision but he had to accept it.

Open Garden Squares Weekend takes place in London this year with 218 hidden and little-known gardens opening to the public on Saturday 14 and Sunday 15 June. The gardens range from the historic and traditional to the new and experimental. They include classic London square gardens, roof gardens, community allotments, urban wildlife and ecology centres as well as the gardens of historic buildings, institutions, restaurants, schools and shops.