Guests dressed as NVA soldiers arrive for their overnight event at the Bunker-Museum near the eastern city of Ilmenau, on October 12, 2013. #

A sign on the bunker entrance reads "Entry only NVA", photographed on October 12, 2013. #

Ingolf Bracher, dressed in an NVA soldier's uniform, poses during a reality event in the Bunker-Museum in Rennsteighoehe, on October 12, 2013. #

Marco, dressed as an NVA officer, opens the door to the Bunker-Museum, on October 12, 2013. #

Protective gear designed to protect the wearer from chemical weapons, inside the Bunker-Museum, on October 12, 2013. #

Participants dressed as NVA soldiers look at weapons displayed inside the Bunker-Museum, on October 12, 2013. #

Glass tubes to control contamination by the chemical poison Sarin, inside the Bunker-Museum, on October 12, 2013. #

The Bunker-Museum's telephone exchange room. #

A can with tomato sauce for a school kitchen, displayed in the Bunker-Museum in Rennsteighoehe, on October 12, 2013. #

37 year-old Andrea Friebe, who works as fitness coach, dressed in an NVA soldier's uniform, poses in the Bunker-Museum. #

A sign of the former Republic DDR, displayed inside the Bunker-Museum, on October 12, 2013. #

Thomas Krueger, dressed as an NVA major, waits outside the Bunker-Museum, on October 12, 2013. #

The Hoppmann family poses in the sleeping room of the Bunker-Museum, on October 12, 2013. #

The Hoppmann family tries on gas masks during their reality event in the Bunker-Museum, on October 12, 2013. #

65 year-old Hans-Georg Tiede wears a gas mask in the Bunker-Museum. #

A man dressed as an NVA officer watches over people during their reality event near the eastern city of Ilmenau, Germany, on October 12, 2013. #

A man dressed as an NVA major speaks to the participants of the reality event at the Bunker-Museum, on October 12, 2013. #

A man dressed as an NVA soldier stands guard outside the Bunker-Museum, on October 12, 2013. #

Thomas Krueger speaks to his guests at the Bunker-Museum in Rennsteighoehe, on October 12, 2013. #

Participants dressed as NVA soldiers prepare dinner during the overnight event at the Bunker-Museum, on October 12, 2013. #

Marco, dressed as a NVA officerr, reads a roster during the overnight event in the Bunker-Museum, on October 12, 2013. #

Participants in the overnight reality event sleep in bunks in a room of the Bunker-Museum, near the eastern city of Ilmenau, Germany, on October 12, 2013. #