The death camp, also referred to as the 'Upper Camp' because it was several feet higher than the rest of the installation known as the 'lower Camp', was surprisingly small. The area encompassed by the security fences only totaled about 22 acres [8.8 hectares]. There were reportedly only a small number of buildings on the site: the old and new gas chambers, the barracks housing the resident Jewish labor force, and a watch tower that was situated somewhere in the center of the area. There were almost no traces found of any of these buildings on the aerial photographs. An exhaustive, persistent and careful examination finally yielded persuasive evidence of the large chamber's position on aerial photos taken in September of 1944. Scarcely any signs could be found of interior security fences. The massive earthworks, resulting from the excavation of the huge burial pits, were not distinguishable. Neither could traces of the pits themselves be seen. The earliest good aerial photos taken in May of 1944 showed only a large area of light toned and sandy soils. The pictures exposed later in September also did not have any signs of the localized excavations. So thorough was the churning of the soils as a result of the repeated digging and backfilling during the camp's active life, that it was not possible to localize, any of the burial sites on the aerial data. However, using a combination of ground and aerial photography and written accounts, the location of the gas chambers was identified, and in one case, the site of a burial pit, opened for the removal and cremation of the corpses. Much of the security fencing was also traced through use of the same sources.
The Gas Chambers and the Tube
The reconstruction was begun with an analysis aimed at precisely positioning the gas chambers. Figure 31 shows two frames of aerial photography in registration.