Dating back to the beginning of 3rd millennium BC, the 5000-year-old city was one of the largest and earliest urbanized settlements in South Asia.
The ruins were first discovered in 1922 and major excavations were carried out in 1930's, however after 1965 further excavations were banned due to weathering and disintegration.
The most irritating censorship is likely to be the increasing number of Wikipedia pages that are blocked; Skype (); and some search terms.
Children looking for feline related material might wonder what they've done wrong when entering one particular synonym for a cat or kitten for example.
Since then, UNESCO has designated six sites in Pakistan as World Heritage Sites and eighteen sites are on the tentative list.