Was instore at WH Smith today in Newcastle-Under-Lyme, you get 4 free vouchers for 2 for 1 entry to quite a few top attractions with any purchase, including:
Bought something for a pound and got them with it. Hope this is useful to someone, not sure if its nationwide, nothing on the voucher to suggest its store specific.
Good timing as alton towers etc are opening within the next couple of weeks.
Theres only a few excluded dates on the voucher (different for each place), but they seem to be obvious times, like christmas day etc..
Im not uploading a photo, i assure you im telling the truth..
First post, go easy!
EDIT: Appears to be nationwide!
EDIT: Online version of terms and conditions (as on the back of the voucher) http://www.merlinentertainments.biz/en/highstreet.aspx