The 66-m-high gas holder was built in the Hecklinghausen district of Wuppertal in 1952 to store and supply mains gas for the city. It went out of use in 1997 with direct supply of natural gas by pipeline. It was protected as a monument the next year. In 2016, the Wuppertal architects GKM designed a new 30-m concrete building inside the tower and preserved the original structure, including the plunger that rose and fell with the volume of gas. Visitors can now walk on the roof of the gas holder to see panoramic views of the region. The upper part of the interior is used as the ‘Visiodrom’ to project 360-degree films 47-m high. In the inserted five storeys below are a gym, a restaurant, interactive displays about the history and conversion of the gas holder and changing exhibitions, which are chosen to give creative energy to the city as gas once gave carbon energy.