The North Entrance to Dover's Western Heights is a grand example of fortification. It comprises two drawbridges across a ditch with a central 'island' called the tenaille, a large road tunnel and underground gunrooms flanking the ditch. It was used as the main road entrance to the Western Heights until the 1960s when Military Road was diverted and a cut was made through the hillside, dissecting the ditch. Fortunately, the unique 1860s entrance was spared demolition but fell into disrepair. It has suffered vandalism over the years, the bridges being reduced to their beams, the gunrooms filled with rubbish and much of the flooring removed. Three large underground water tanks in vaulted chambers were also filled with spoil from the building of the road. The complex was sealed for many years, with periods of accessibility due to vandals and is now owned by English Heritage. The Western Heights Preservation Society have worked to clear the site and have made public access possible on Heritage Open Weekends.