National Gallery sleepover prize draw offers chance to dream among paintings

London gallery's competition marks 200th anniversary and opening of Sainsbury Wing after two-year overhaul

As far as sleepovers go, it's a one of a kind: an overnight stay in a luxury bed in the middle of the National Gallery's exhibition rooms, dreaming under the world's greatest paintings.

Perhaps you'll be inspired by the venerated artworks to pick up a paintbrush, or you'll have a surreal experience like Ben Stiller in Night at the Museum, whose character - a night security guard - finds its exhibits come to life after sunset. You could even unearth a long-buried conspiracy, and find your discoveries adorning the pages of the next Dan Brown novel.