Visitors to a national park are being invited to join the hunt for hidden secrets.
A family geocache trail has been set up in the Hope Valley in the Peak District as part of celebrations by the British Ecological Society.
The organisation is marking its centenary this year.
Families or groups can borrow GPS units from Castleton Visitor Centre to help them find the hidden caches.
The containers reveal special activities to help them find out about the wildlife, geology or history of the area.
The geocaching days are on Saturday 8 June, Sunday 14 July, Sunday 4 August and Friday 9 August, when staff from the Peak District National Park Authority and National Trust will also stage free activities, including stream dipping and mini-beast hunting.
Sarah Wilks, from the national park’s learning and development team, said: “The geocache trails add a bit of anticipation and excitement to a walk in the countryside.
“They enable people to use technology and mapping skills to learn about the national park, its wildlife and special qualities, in a way that should appeal especially to families with children or young people.”
The Geocache Trail will take around two hours. Visitors with their own GPS units can download a guide or pick on up from the visitor centre from 8 June.
More details can be found on the Peak District national park website or by calling 01433 620373.