The one in Golkonda, a ruined fort a few killometers west of Hyderabad, in the South East of India. Actually, it is not just a fort: it is a complex which used to be the the capital of the ancient kingdom of Golconda, between the XIV and XVI century. Almost 800 years after, it is still impressive.
Hyderabad’s role in the pearl trade has given it the name, “City of Pearls” and up until the 18th century, the city was also the only global trading centre for large diamonds.[17][130][131]
Long story short, around 1590 the capital was transferred to the neighbour city of Hyderabad, historically known as a pearl and diamond trading centre. It still is known as the City of Pearls, much for my banker’s dismay. Other than pears, it has become a global centre for information technology, in a part of the city better known as Cyberabad. Strangely enough, as far as I could feel, wifi was a scarce resource only available to a chosen few.