Out in the arid Kirthar hills of Sindh, far from any city, a wall climbs and dips across the bare mountains for as far as the eye can see. This is Ranikot, the "Great Wall of Sindh", and it is a serious contender for the title of the largest fort in the world. Its ramparts trace a circuit usually measured at around 26 kilometres, some estimates run higher, enclosing roughly 65 square kilometres of rugged valley and ridge. Standing at one of its gates, watching the fortification snake over the next summit and vanish, it is easy to understand why visitors reach instinctively for a comparison with the Great Wall of China.
The most remarkable thing about Ranikot is how little we truly know about it. No one can say with certainty who built it, or exactly when, or why. There is no ruined city inside, no clear record, only theories that reach back across two thousand years. Some attribute it to the Sassanid Persians, others to the Greeks, others to the Abbasid governors of the ninth century, and local scholarship has linked an inscription found on site to the Gupta era of the third to fifth centuries. What is better documented is a major reconstruction in the early 19th century: around 1812, under the Talpur rulers of Sindh and the direction of the minister Nawab Wali Muhammad Leghari, large sections were rebuilt at the enormous cost of 1.2 million rupees, which is why the masonry of the gates looks so much newer than the ancient walls behind them.