Mention the main evidence to suggest that the Indus Valley people paid great importance to sanitation and health.
The elaborate drainage system was there in the city. A brick-lined drainage channel flowed alongside every street. The house drains were connected to underground main drains, which opened into large brick culverts on the outskirts of the city. The drains were provided with manholes. This provision of such a systematic drainage system in every city shows that the people paid great attention to sanitation and health.