The Ramayan Circuit Bus Route connects Janakpur, 225 km from capital Kathmandu, to Ayodhya.
"I am confident that my visit will further cement our people-centric partnership with Nepal on the basis of mutual benefit, goodwill and understanding," PM Modi said in a statement on day-1 of his visit.
This morning, he visited the iconic Muktinath temple and Pashupatinath temple later. He will also meet political leaders in Nepal.