Domus Aurea

After the Great Fire of Rome in 64 AD — which Nero was rumoured, probably unfairly, to have started himself — the emperor seized a huge swathe of newly cleared land in the city centre to build the Domus Aurea, an extravagant palace complex of gardens, an artificial lake, and lavishly frescoed halls that ancient sources describe as scandalously excessive even by imperial standards, complete with a rotating dining room ceiling and a 30-metre bronze statue of Nero himself at the entrance.

The backlash was immediate after Nero's death in 68 AD: his successors deliberately buried and built over the Domus Aurea as a political statement, erasing his excess from the cityscape — the Colosseum itself was built on the site of Nero's artificial lake specifically to return the land to public use. Ironically, that burial preserved the palace's frescoed rooms remarkably well, sealed underground and forgotten until Renaissance-era treasure hunters accidentally broke through the ceiling of one room in the 1480s and lowered themselves in by rope to see frescoes no one had viewed in 1,400 years — an experience that directly influenced Raphael and other Renaissance painters, who copied the whimsical, hybrid figure-and-foliage decoration ("grotesque" style, named for these underground "grotto" rooms) into their own work at the Vatican.