But no one I have mentioned it to has heard of it. In fact, people tend to express surprise that a place like that even exists – a place where anyone can be granted a rendezvous with Rembrandt.

Secret studies

London has many secret sanctuaries, but none are quite as magical as its hidden study or reading rooms. Many museums will have one; some are very grand indeed. With its chandeliers and ornate ceiling, the reading room of the National Art Library at the Victoria & Albert Museum could be mistaken for a ballroom.

On a more intimate scale, the genteel reading room at the London Library in St James's Square has attracted book lovers for almost two centuries. AS Byatt honoured it in the opening scene of her best-selling novel Possession: "It was shabby but civilised, alive with history but inhabited also by living poets and thinkers who could be found squatting on the slotted metal floors of the stacks, or arguing pleasantly at the turning of the stair." The prints and drawings room at the British Museum is filled with a similar atmosphere – a sense of creative correspondence across the centuries.