Why is this monument famous?

Question

This is the picture of a monument associated with the founder of a religious reform movement in India.

Why is this monument famous?

Answer 1

This monument is famous for its teachings 

1. All human beings are equal and God is only one. 

2. All religions must be respected. 

3. Fasts and other rituals are not necessary. 

4. There is no need to convert to another religion.