12/18. Many people are unaware of the importance the British Isles plays in the survival of Ancient Trees. We all look at these venerable old trees in parkland but do we ever think that they should actually be viewed as the Old Masters of the British countryside? In this week's Living World, Lionel Kelleway travels to the Croft Abbey estate in Herefordshire. Here, inside the hollow belly of a 700-year-old oak, Lionel meets Brian Muelaner, an Ancient Tree advisor with the National Trust, and professor of mycology Lynne Boddy. Apart from the inherent beauty an individual tree has in a parkland landscape, as a group, Ancient Trees are vital to the survival of many fungi in the landscape. And without fungi, the trees would be unable to survive at all. With a changing climate, can this symbiotic relationship have a future? Or are we seeing the last of these trees forever? Croft Abbey estate is remarkable because of its continuity of ownership over many generations by the same family who, like us, valued their ancient trees for aesthetic, not commercial, value. Hidden away in a corner of the parkland is Britain's oldest sessile oak, gnarled and twisted by age, but at over 1000 years old it could live for many centuries to come. Nearby, an avenue of sweet chestnuts, planted from seeds washed up after the Spanish Armada failed in its mission, majestically recreate the Spanish fleet's formation at sea on the hill. Presented by Lionel Kelleway Produced by Andrew Dawes.