Why we celebrate chaat pooja?

It is one of the most important festivals celebrated by hindu it comes after Diwali is known as Chhath Puja. Chhath Puja is a festival devoted to Sun and his wife Usha, who is also known as Chhathi Maiya. There is another story why we celebrate chhath Puja that Draupadi and Pandavas celebrated this festival in Hastinapur to solve their problems and to get vack thrir lost kingdom.It is ine of the most important festival.