The lead author on this paper first surfaced these claims in 2013, and later that year published a book called “ Plato Never Lied: Atlantis Is In Indonesia”.
Reading the actual paper, I’m having a tough time visualizing the “sculpted” aspects of Unit 4. This is supposedly the volcanic core that was carved bw 20k and 15k BC. Based on the dating of the other layers, it seems much more likely that a volcano erupted there like 50k years ago and slowly eroded, right? Hilman’s got that diagram of the site labeled with “tunnel” and maybe that’s a translation thing, but the tunnel is right where you’d expect a volcanic conduit to be. He also uses the suggestive term “chamber” elsewhere. There’s no debate that this is an old volcano btw, and no debate that there is an interesting ancient structure (500 AD) on top of the hill. It’s the “carved” internal structure that seems like a big big stretch.