In Hyderabad in southern India, I gave two talks to students and research scientists at the NGRI- National Geophysical Institute of India, one of India’s major research centers in multidisciplinary areas of Earth Sciences. They have impressive laboratories and facilities. The NGRI compound is a nice respite from the busy city.
We visited Fort Golconda, a massive fortress built on a granite hill in the 12th century. The enormous fort is a UNESCO World Heritage site, with several mosques in it.
I was particularly fascinated by the hand cut stone masonry, precisely fit around huge boulders to comprise the thick, impenetrable walls.
A major acoustical engineering feat is the signaling system where a hand clap at the dome at the entrance will reverberate up to the hilltop pavilion, the highest point ~ 1 km away to announce visitors or warn the royalty of any attack. Famous diamonds (like the Hope and the Koh-i-Noor Diamonds) were extracted from the Golconda area.