They do many events throughout the year and most people would say go in autumn when the leaves are changing colour. I suggest go in winter as they do an Enchanted Christmas walk through a mile of trees illuminated in the winter night sky. A fantastic time to walk the grounds wrapped up warm with your family and dogs. An absolute must.
www.forestry.gov.uk/westonbirt
Tetbury, Gloucestershire GL8 8QS
+44(0)1666 880220
Google map: bit.ly/R6Oz8H