Activities to entertain the children are taking place at Upton House near Hornton on August 2 and 16.
Wildlife and nature charities will be hosted by the estate and there will be pop-up stands, outdoor nature trails and a chance to find out more about hedgehogs.
Two young hedgehog rescuers, 12-year-olds Kyra and Sophie, from Hedgehog Friendly Town (part of Warwickshire Hedgehog Rescue) will be there.
The pair has cared for over 165 hedgehogs, has won the Pride of Stratford-upon-Avon award and has been featured on BBC Countryfile, Midlands Today and The One Show.
They will tell visitors all about hedgehogs and people can make their own clay hedgehogs.
Other craft opportunities will include making your own bottle bird-feeders with Warwickshire Wildlife Trust while Warwickshire Mammal Group will invite people to do an owl pellet analysis.
Other groups at the event include Warwickshire Badger Group, Upton House Garden Volunteers, Bumblebee Conservation Trust, Warwickshire Geological Conservation Group, Warwickshire Butterfly Conservation and Warwickshire Bat Trust.
Details on which charities will be at Upton House on each day can be found at www.nationaltrust.org.uk/upton-house-and-garden.
Normal admission prices apply, all additional activities are free to enjoy.