Worth the visit, but about £11 p/person for full entry if your not NT members.
Old Hall, New Hall, and the gardens have seperate prices to visit them.
It works out cheaper to pay the full fee for full entry to all, and visit all in one go.
I'd not pay £6 just to see inside the Old Hall alone. Or £5.50 just for the gardens.
Photography is allowed, but no flash, hence the dark indoor pictures.
New car parking, shop, restaurant, toilet block, baby changing facility etc
If you've not been, consider going

Review over
