The Browndown Ranges include practice trenches at Browndown North used by troops during World War One before being deployed. The trenches had been covered and preserved by vegetation and were discovered in 2011. Browndown is still an active military training site and visitors must not enter the site when the gates are locked or when red flags are on display. More details about the site and the walk routes can be found here:

https://historicengland.org.uk/whats-new/research/browndown-training-for-trench-warfare-in-the-first-world-war/

https://theoutdoorguide.co.uk/walking-routes/mottes-and-trenches-walk/