Invicta Airsoft used to have access to the Lydd ranges and holy hell there was some cool stuff down there which were like Sennybridge! Don't know why nobody else hasn't tried to get back in on that action tbh!
There was a similar site at Fort Amherst in Chatham... don't know if anyone still operates it, but that was good fun.
However, I can see on the listing it's already under offer.
Since CAGE/Invicta folded there's a bit of a dearth of sites in East Kent :(