George Clarke's Amazing Spaces can be viewed on Channel 4 and 4oD from Thursday 24 October 2013. The Sky Den Tree House is George Clarke's newest project, for more information about the Sky Den Tree House please email skyden@kielder.co.uk.

Calvert Trust Kielder is a registered charity based in Kielder Water & Forest Park in Northumberland. Calvert Trust Kielder provides adventurous outdoor activity holidays and day visits for people of all abilities. For more information on other self catering holidays, activity days or respite care holidays please email enquiries@calvert-kielder.com.

Calvert Trust Kielder, Kielder Water & Forest Park, Hexham, Northumberland NE48 1BS. www.calvert-trust.org.uk/kielder.

Registered Charity No. 511851. Company limited by guarantee. Registered in England No. 1596913.