Ajmer is a very busy city in the heart of Rajasthan. The city is known for its Dargha Sharif, a holy sufi shrine. The streets around the shrine are totally crowded with pilgrims from all over the world.
Beyond the Nag (snake) mountains lie Pushkar, the quiet holy hindu city. The only temple dedicated to the God Brahma is in Pushkar. The holy pound is surrounded by a multitude of "Ghats" through which you have to walk to make Puja (prayer) with one of the numerous (and sometimes money attracted) brahmins.
Pushkar and its atmosphere of colorful spirituality  was a first choice destination for the hippies in the seventies. It's still very attractive for post-hippies and self-called "alternative" travelers.