Museo storico della fisica e Centro studi e ricerche Enrico Fermi

Its own site gives two addresses, and both are correct because they are two doors of one building. The registered office and postal address is Via Panisperna 89a, 00184; the visitor entrance is at piazza del Viminale 1, 00184. That is why other records place the museum on piazza del Viminale while OpenStreetMap places it on via Panisperna.