More than anything else, old buildings etc.we need to preserve our rivers, as water is the most useful natural resource we are blessed with.We have so many rivers, lakes and other water bodies.But we neglected them and misused, abused them and now at the brink of losing them. Though we worship them but have not shown any respect and do not keep up their purity and pollute them in the name of religion and culture.
So many lakes and ponds have died due to construction of residents. Greed of builder knows no bounds. Nobody bothers about what we are going to leave to our next generation.
If I could single handedly prevent something from falling into oblivion then it would be our rivers, sacred rivers like, Ganga, Yamuna, Brahmputra, Narmada, kaveri etc. and many lakes from being extinct before people start killing each other for water. No other object is that much important for me except water.