The largest indoor complex in Hungarian railway history, a system of vast covered spaces unique in Europe, the Northern Railway Maintenance and Engineering works was built between 1884 and 1886. As activities on the 22-hectare site ceased in 2009, the government offered 6.7 hectares of the area to the OPERA together with the five-nave core repair complex of 22,000 square metres, named after Eiffel, two auxiliary buildings, and a complete train station. The rehearsal, production and storage centre for the OPERA was built here where the Bánffy Stage, with an auditorium with 400-600 seats, was constructed as well as the Sándor Hevesi rehearsal stage of the same size as the stage of the Opera House, and the Ferenc Fricsay music studio suitable for recordings. In addition to moving all of its nine production workshops, all of its sets, costumes and props here, the institution also creatde a memorial room for János Feketeházy, the designer of both this building and the Opera House’s iron skeleton. The official inauguration of the Eiffel Art Studios that had already had a test run since spring 2019 took place on 25 October 2021, whereas the entire project is expected to be completed by late 2023. Afterwards, work can begin on the adjacent Hungarian Museum of Science, Technology and Transport. The complex was redesigned for the unique purposes of the OPERA by the KÖZTI architects’ studio led by Ybl Prize recipient Miklós Marosi in 2015.