We visited the Golkonda fort and Qutub Shahi tombs. Navin is very passionate about what he is doing, that is why, i think, it is quite a pleasure to have him as a guide.
The his/tory can be boring if the teller is just reciting facts and names. It is not boring to listen to Navin at all. He is knowledgeable, funny, friendly, and glad to answer all your questions. It was a memorable experience.
The tour will take around 4 hours. Come prepared, the Golkonda is huge, with a long walking up. Wear proper shoes, hat. And take a panoramic picture when you get to the top.