UK retailer WHSmith is offering a free booklet containing four 2 for 1 theme park vouchers with any purchase from April 11 - 17, 2011. The vouchers are valid at Alton Towers, Chessington World of Adventures, Thorpe Park, and Legoland Windsor along with a number of other UK attractions operated by Merlin Entertainments Group.

To get the vouchers, all customers need to do is buy anything from a WHSmith high street or travel store. There is no minimum spend, so even those buying a newspaper or some chewing gum for a few pence will get the vouchers.

There has not been an official end date stated as to when vouchers will stop being given out. If you try to get a voucher booklet and they are no longer giving them out please email us to let us know.

The vouchers can be used when buying a full price adult ticket on the day (at the higher gate prices rather than discounted online tickets). A single adult ticket bought on the gate costs £39.60 at Alton Towers. With two online adult tickets costing £63.36, there is a potential saving of over £23 from taking advantage of the offer.

The vouchers are valid through most of the 2011 season, but there are some block-out dates on which they can't be used:

• Alton Towers - Valid until November 4, 2011. Block-out dates: June 19 and 29, 2011.
• Thorpe Park - Valid until November 6, 2011. Block-out dates: April 22 - 25, October 22 - 31, 2011.
• Chessington World of Adventures - Valid until October 31, 2011. Block-out dates: all Zoo Days.
• Legoland Windsor - Valid until November 6, 2011. Block-out dates: The whole of August (note that the park is closed on some days during the season).

As well as the four theme parks, other major attractions included in the offer are Madame Tussauds, Warwick Castle, The Dungeons, Legoland Discovery Centre and Sea-Life Centres and Sea-Life Sanctuaries across the country.

For full terms and conditions visit the Merlin Entertainments website.