FREE to all comers a single or double National Art Pass.
It's valid for three months and you have to apply before midnight on Friday, April 12th, so get your skates on.
Basically you can enjoy for three months unlimited free admission to over 200 charging museums, art galleries, castles and historic houses. Plus 50% discount on some high profile exhibitions.
There doesn't seem to be a catch, you do have to sign up to newsletters, but that's how I heard about this amazing offer in the first place, so no hardship there. I've applied for a double pass which normally costs £59.50 per annum. I've already picked out several museums and a couple of palaces I want to visit.