There’s nothing quite as good for the soul as a walk in the woods, but you should consider that some trees have lived in forests for many, many years. Ancient Woodlands are areas of trees that have existed since at least AD 1600 and have developed irreplaceable, complex ecosystems. Ancient Woodland accreditation is based on an assessment of the available evidence that includes checking the Ancient Tree Inventory (https://ati.woodlandtrust.org.uk) and any historical features, examining old maps and documentary evidence, and assessing the species which occur on a site. Areas granted this accolade are largely undisturbed by humanity. It is believed that only 2.5% of the UK holds this status, the largest being Wyre Forest located on the border shared by Worcestershire and Shropshire, which is equivalent to 1700 football pitches!
