India has a rich history, going back to beyond 3000 BC with the beginning of the Indus Valley civilization. This civilization was one of the world's earliest urban civilizations, and is praised for its cities of brick and functioning drainage systems. This period was followed by the Aryan migration to India, starting in the 1700 BC. This era saw tremendous growth in what we now associate with Indian culture. This was followed by the Mughal invasions and many of the existing architectural monuments were built during this time. The most recent Indian history includes the British invasion of India and the struggle for independence.