President Pratiba Devisingh Patil and Prime Minister Manmohan Singh today led the nation in paying rich tributes to the country's first Prime Minister Pundit Jawaharlal Nehru on his 121st birth anniversary.Mrs Patil and Dr. Singh paid floral tributes to the architect of modern India at Shanti Van in New Delhi amid chants of vedic hymns and songs by a group of students.Vice President Hamid Ansari, UPA Chairperson Sonia Gandhi, Delhi Chief Minister and Sheila Dikshit were among the prominent persons who paid floral tributes at the memorial. Later, Dr.Singh,Mrs. Gandhi, Lok Sabha Speaker Meira Kumar and BJP leader L K Advani paid floral tributes at Nehru's portrait in the Central hall of Parliament.Cultural programmes were organised in city schools as the day is also observed as Children's Day. Nehru was fond of children and was known as Chacha Nehru during his lifetime.