The Red Fort The reason why I think the Red Fort would be heritage of the future, is because of many events that took place there. The Red Fort is a landmark of Indian History.
The Jantar Mantars The reason why? These observatories are loaded with accurate instruments by Maharaj Jai Singh II are a part of Research from Ancient India.
The Taj Mahal It's because the Taj Mahal is simply a perfect reflection of India. The perfectly Symmetric building is clearly Future Indian Heritage.