A report on Nero exhibitions in Germany this year made me aware of the claim that the octogonal dining room - coenatio principalis - of his palace Domus Aurea in Rome had either one rotating dome or several nested ones in order to display celestial motions 1),2),3). Or - since there is no archaeological evidence for such mechanisms - that there was a fixed dome with moving lanterns instead 4).
The only contemporary source seems to be one line in a text by Gaius Suetonius Tranquillus - and Ref. 5 says that scholars "have long debated whether this planetarium-like aspect of the room was a marvel of Roman engineering or simply a figment of Suetonius' often whimsical imagination." Is there a consensus by now about what clever astronomy display system was or wasn't installed in the Domus Aurea? And what about an even better 'planetarium' in Domitian's Domus Augustana Ref. 1 mentions?
1) Dewdney, Acquainted with the night
2) von Stuckrad, Das Ringen um die Astrologie
3) Merola, Rome's Domus Aurea
4) Goesl, Modern Projection Planetariums as Media of Iterative Reinvention
5) VROMA, Photographs of Domus Aurea