Hidden Chambers at 12,000 year old megalithic site of Padang

Graham Hancock going to visit Gunung Padang
Note: 2 of the picture is from another location, number 3 and 8 from bottom...
source:
one-vibration.com... -an-eerie?

Gunung Padang exist in ancient Indian text??
Source:
jayasreesaranathan.blogspot.com...

Another link in Bahasa Indonesia:

Two level of culture 600 BC and 4900 BC confirmed.
Source:
www.rmol.co...:-Dua-Level-Kebudayaan-di-Gunung-Padang-100-Persen-Terbukti!-

Ancient cement (41% mono crystal quartz, 45% Ferrum Magnesium Oxide and 14% clay) exist.
Source:
javanews.co...

Do we have here in ATS, someone with expertize to confirm, is this a good cement composition?

Edit: I don't know why the links broken, please add the other words after the links, that's part of the links