If you pay once as we did to go to Blenheim Palace Christmas opening and display, and then upgrade your ticket to an Annual Pass for free, and you live within a day trip of the attraction then you have excellent value from your ticket.
You can revisit as much as you like, and we have spent a morning in the gardens, two separate days visiting the Palace looking at the State Rooms on one visit, and the Untold Story on another which has moving figures and touch screen technology.
Then there is the Butterfly house and Marlborough maze with adventure play area for children connected to the house by a miniature train.
You can also pay for a tour of the private apartments which we found worthwhile.
The Pass includes the Park and some events so there are many opportunities to have an enjoyable re-visit over the year.