President Pratibha Patil on Friday began her two-day visit to Bihar amid tight security.
She is scheduled to attend several official functions in Gaya and Patna during her visit - the first to the state since assuming office in July 2007.
The state home department sources said she arrived at the International Airport in Gaya, about 100 kms from Patna, in the morning and left for Nalanda to see the remains of the ancient Nalanda University.
She will return to Gaya on Friday afternoon and visit Mahabodhi temple in Bodh Gaya, where Buddha is believed to have attained enlightenment about 2,550 years ago.
Officials said the president would also inaugurate a cultural function, Tarang, at the Magadh University in Bodh Gaya before returning to Patna.
She will visit the Sikh holy shrine Takht Saheb in Patna on Saturday morning and participate in two programmes, Kanya Suraksha Yojana and Mukhiya Mantri Kanyadan Yojana.
She will also visit the Vaishaligarh, Shanti Stupa and other historic sites in Vaishali district on Saturday.