It would certainly be wonderful to see inside. Photographs taken by previous visitors show that many of the ancient frescoes are (or were) still visible.
Pretty good condition, considering they were painted in 64-68AD.
This video gives you a rough idea of how Nero's 'House' (which actually encompassed many buildings, a lake, and wide tracts of land) is positioned beneath the Rome of today.
Unfortunately, the parts of the palace that have been excavated are no longer open to the public. Plagued by structural problems and cave-ins, the site is now out of bounds for safety reasons.
As this tourist website explains:
"Having finally been reopened to visitors in 1999, the Domus Aurea closed again in 2005 because of water damage, to reopen once more in January, 2006 and then close again in December of the same year. It became a building site and this was briefly open to visitors in 2009, only to close again as a result of collapses on the 30th March 2010. Nobody is even talking about when Nero’s ‘Golden Palace’ may reopen, but it will be years, for sure. There is no way to visit and we are unable to take bookings."
This video shows some of the damage from the 2010 collapse.
Of course, I knew all this before traveling to Rome. Ultimately, I decided to go anyway, because I figured just being there would be special. And it was.
The area around and over the Domus Aurea excavation has been turned into a shady park with lots of trees, seats, and drinking fountains. Many go there to escape the midday heat, lying around and even bathing. [No, I didn't take any pictures of that. For your own protection, people.]
In some places around the tunnels it does look like a building site.
You can look, but you can't touch.
The entrances are all blocked off. Very sad.
The grotesques... can't you hear them calling?
Maybe it's just me.
This is where tourists would enter when the site was open.
So very jealous. One of these lucky individuals took a video, so we can see a little of what they saw.
This statue, the Seated Muse, is visible in the above video...
...and I did get to see the lady herself in the Colosseum, where a small exhibit has been set up in honour of the Domus Aurea.
This exhibit also includes some images of the interior, an artist's impression of the Domus Aurea, and a brief write-up on Nero's aesthetic.
"Artifice and an attempt to control nature are two of the main inspirations of Neronian architecture applied to the emperor's most famous project, the Domus Aurea. This was the residence that Nero intended to be a suitable backdrop for his regal majesty and divinity... Tacitus relates that the work was entrusted to two brilliant architects, Severus and Celer... [who attempted to] reshape the natural character of places to recreate the mythological and idyllic landscapes typical of the Horti, also found in paintings of the period. In the enourmous space available, man-made structures appeared between the woods, gardens and ponds, creating breathtaking new panoramas, enchanting views of artificial lakes, and bucolic scenes, probably peopled by statues."
Of the inside:
"One of the most important features of Neronian architecture was the luxury of its interior decoration (the floors, marble wall revetments, stucco and frescoes, mosaics, sculpture, and so on), which were intended to overwhelm the viewer. The splendour of the Domus Aurea must have been exceptional, even though little of it remains today, not even in the surviving pavilion on the Oppian Hill which has been robbed systematically of its marbles... The rooms of the pavilion permit a partial reconstruction of the appearence of the painted decoration, which Pliny the Elder (XXXV, 120) attributed to the painter Fabullus (or Famulus), praising the attention given to the colour tones and the preference given to mythological themes. The surviving frescoes are evidence of the influence that the emperor's tastes had on the choice of themes."
There are other remains to visit nearby, including Trajan's Baths, which were built on top of the Domus Aurea when it was destroyed.
Segments of the original mosaic are still visible on some pieces of flooring.
Overall the site is, I think, still worth visiting if you have an interest in the grotesque and its history, although most won't bother. Hopefully the tunnels can be restored enough to permit visitors again, as this is what will keep the place alive.
In the meantime we will have to make do with pictures and other virtual explorations.