Some of the best of these are to be found in the Midlands and the northern half of England.
Thanks to players of People's Postcode lottery, the National Trust has, to date, received more than £5 Million to help it look after these special places so that everyone can enjoy them.
Stacey Hall from National Trust has put together a list of recommendations. Stacey said:
"As summer rolls in, signalling weeks of downtime for kids on school holidays, where better to capture restless minds and imaginations than exploring a castle and its grounds?”
Wentworth Castle Gardens in South Yorkshire has a classic fairytale castle feel. You get two for the price of one with the smaller Stainborough Castle built within its gardens. It's also home to more than 150 deer, bats and wild birds.
Stainborough looks medieval but was actually built in 1731 by Thomas Wentworth to give the impression his family had lived there for centuries. Don't miss Lady Lucy's Walk for pop-up sports activities such as archery, athletics and football, plus a fantastic play area.
Oxburgh Hall in Norfolk has what every castle really needs - a moat. The venue is hosting a Summer of Play where children can test out their badminton skills or play giant chess or Jenga. Lively imaginations will jump at the chance to dress up as a builder and build their own estate. Or how about making friends with a death watch beetle and hearing the scary noises that gives them their name!
The Children's Country House in Sudbury near Uttoxeter in Derbyshire is a destination to have fun with history. The Museum of Childhood charts work, rest and play through the ages. And the gardens include nature trails with hidden sculptures and picnic areas.
Interactive exhibits inside the house highlight the tougher realities of childhoods past, including the chance to dress up and experience life in a Victorian-style classroom, and a display of toys through the ages. One of the starker reminders of days of old is the Victorian mine tunnel, where children can climb and crawl into the darkness to really get a feel for what it would have been like for real-life chimney sweeps!
Wray Castle on the shores of Lake Windermere in Cumbria offers plenty of options for families to create fun memories, from lawn games to a scenic boat cruise across Lake Windermere. Or join in with some of the planned activities from hula hooping to badminton tournaments. There is guaranteed fun and competition for all the family on the lawn every day until 3rd September - and it's absolutely free.
Wray is a fab spot for picnics, with endless mountain views. Bring your own supplies or pick up food and drinks from Joey's Cafe in the grounds. And if the weather is kind, go for a paddle but remember your swim shoes for the shingle shore!