Westonbirt Arboretum is almost in Wiltshire. The boundary of the county follows the A433 which brings you to the entrance, but once inside the wood you are in Gloucestershire. But it does mean that it is an easy place to get to from Wiltshire, but since it is nationally famous for its Autumn colours it would be a stretch to regard it as truly "hidden". So while it is worthy of a visit, I don't include this entry on the list of site for Hidden Wiltshire.
It is a magnet for visitors in the Autumn because of the stunning array of colours. The arboretum contains many non native species from across the globe and parts of it are designed to impress at this time of year. Vivid reds compete for attention with bright orange and yellows. You are spoilt for choice when it comes to photography, and by the end of my visit to the Old Arboretum and Silk Wood I had seen so many bright colours that my interest in Autumn colours was saturated.
The planting dates back to the Victorian era, with much of the trees and shrubbery being planted in the mid 1800s. The Old Arboretum has been deliberately designed to show off its splendour, with wide avenues and beautiful views. The much bigger Silk Wood is more like a traditional woodland, but is also dotted with Acers and suchlike making it multicoloured in October and November.
We have visited the Old Arboretum at night in the run up to Christmas, where they have an array of splendid lights to illuminate the forest and make it a fabulous place to go on a frosty night at Christmas. It is truly an enchanted forest.
Royalty is not far from here too. The Arboretum itself backs on to the Highgrove Estate, the country residence of Prince Charles, the Prince of Wales.