The Buddhist site of Sarnathis a popular excursion from Varanasi. It's there where Buddha came to preach after his enlightenment.
My suggestion
If you have visited Bodhgaya during your trip to India, it's not worth you going to Sarnath because it would be superfluous, unless you have a particular interest for sacred places of Buddhism.
For a lot of travelers in India, New Delhi is the capital of everything that they need to get away from as quickly as possible. Nevertheless, the town has some wonderful secrets that I would like to share with you.
In the local dialect, "Apani Dhani" means "Our Hamlet", an affectionate name given to the place by Ramesh C. Jangid, founder of the ecolodge and a pioneer of a form of militant tourism in India, especially in Rajasthan and his own native region of Nawalgarh.