Rajgir was the capital of Magadha over 2,500 years ago. The Buddha and Mahavira both spent time here. Mahindra Group Chairman Anand Mahindra on Sunday described Bihar as a potential "tourism gold mine", saying the state's extraordinary historical and cultural heritage deserves far greater attention from travellers.His remarks came after a video of Rajgir prompted him to explore the state's ancient history, Buddhist heritage and modern tourist attractions.