N.V. brickworks factory has over time led to the rediscovery of several World War I underground structures. Zonnebeke's underground war legacy Today the district of Zonnebeke and its five villages – located at the centre of the area devastated by the Battle of Passchendaele – have the largest concentration of recorded World War I underground constructions. Most deep dugouts are now flooded, which has helped to preserve them, and they are now the most authentic relics of the Great War in Flanders. In addition to the Vampire dugout, 171st Tunnelling Company also constructed a deep dugout in the centre of Zonnebeke, located directly beneath the ruins of the parish church. This dugout was only discovered during archaeological excavations of the Augustinian abbey. Today the outline of this dugout is marked in an archaeological garden within the church grounds, and a model of the church dugout can be seen at the "Memorial Museum Passchendaele 1917" in Zonnebeke. About 180 dugout sites have been located in the Ypres Salient and in the 1990s some of them were entered, at least in part. In 1983, the Australian-built Bremen Redoubt was discovered at the rear of the Terca Zonnebeke N.V. brickworks in Zonnebeke. Opened to the public until 1998, it is believed that its eventual collapse was due to drying support timbers. On 21 February 1998, a farmer’s wife disappeared into the ground while washing the windows. Beecham dugout was subsequently discovered less than from Tyne Cot Cemetery. Rediscovery of the dugout In spring 2006 it was made public that the Terca Zonnebeke N.V. brickworks had received a licence for the extension of its blue clay extraction zone. In response, research by the Association for Battlefield Archaeology and Conservation (ABAC) carried out by the Belgian tunnel explorer Johan Vandewalle and the British historian and filmmaker Peter Barton, who compiled a directory of 350 World War I underground structures, managed to show that at least one such structure, believed to be Vampire dugout, was near the proposed brickworks development zone. Following discussion with local preservation, council and state officials, the ABAC was allowed to start a formal research project into the Vampire dugout's history. In light of the Highland Light Infantry's use of the dugout, the ABAC also involved the Centre for Battlefield Archaeology at Glasgow University to provide archaeological support. Excavation and exploration After further map analysis in 2006, a joint Belgian/British team led