This is one of the largest forts in the world, situated in the Indian state of Rajasthan. The fort stands proudly amidst the golden stretches of the great Thar Desert, on Trikuta Hill and had been the scene of many battles. The famous Indian film director Satyajit Ray wrote a detective novel and later made it into a film — Sonar Kella (The Golden Fortress) which was based on this fort. Identify this fort.