The Indus civilisation, also known as the Harappan civilisation or bronze age urban civilization, was India's first well-developed mature urban civilisation. Between 2500 and 1900 BC, the civilization reached its peak, as evidenced by features such as the citadel, lower town, brick buildings, large bath, seals and sealings, irrigation, breeding habitat, technology, arts, religious traditions, undeciphered Harappan script, weights and measurements, stone work, metal pictures, and so on.