Ferris wheel was left standing for some time after the festival was over. While there were rumors that the Americans had excavated a shaft down into the ruins beneath, that was never proven, and was likely based on reports that those who maintained equipment in one of the first enclosed antenna structures accessed the upper levels of the inflated dome via an airlock that led to a "tunnel" that was embedded in the structure's central column. Speculation as to what might have existed within the highly restricted area frequently gave rise to rather elaborate but false rumors; one theory stated that "the tunnel" was an underground escape route, another that it housed a submarine base. In the 1990s, as Berlin experienced an economic boom after German reunification, a group of investors bought the former listening station area from the City of Berlin with the intention to build hotels and apartments. There was talk of preserving the listening station as a spy museum. Berlin's building boom produced a glut of buildings, however, and the Teufelsberg project became unprofitable. The construction project was then aborted. As of the early 2000s, there has been talk of the city buying back the hill. However, this is unlikely, as the area is encumbered with a mortgage of nearly 50 million dollars. The site has been heavily covered in graffiti since the company abandoned the project. Since 1996, the site has been privately owned and is currently fenced off from the surrounding forest. In the summer of 2016, landlord Marvin Schutte opened the site to visitors who are able to climb the listening station towers and admire the ever-evolving "street art gallery" that fills the site's abandoned buildings. The site and buildings have uneven surfaces, broken glass, and building debris. Accessing the main dome involves ascending a pitch dark stairwell in the centre of the building. As of April 2017, entry to the site is €8 payable at the main entrance gate and a sign informs visitors that it is open from 10am to "one hour before sunset." Following the announcement of plans to raze the facility and reforest the hill, talk of preserving the facility resurfaced in 2009, spearheaded by the Field Station Berlin Veterans Group, which hopes to have the memorial named in honor of Major Arthur D. Nicholson, the last military Cold War casualty, the U.S. Military Liaison Mission tour officer who was