Jodhpur, Rajasthan's second-largest city, is known as the Blue City because of the pale blue-painted narrow and tall houses of the jumbled and entrancing medieval Old City, which are especially impressive when viewed from the ramparts of Mehrangarh Fort. The city, at the base of a sandstone ridge, was the capital of the Marwar kingdom for five centuries, and it's encircled by a 9-km (6-mile) wall, which keeps out the desert sands. It was named after its 15th-century founder, Rao Jodha, chief of the Rathore clan of Marwar. The clan traces its lineage to Lord Rama, hero of the ancient Hindu epic The Ramayana.
There isn't that much to do in Jodhpur, aside from a few sites including the incredible Mehrangarh Fort, and some textile shopping, and many people use the city as a jumping-off point for Jaisalmer, or as a place to overnight on the way to Jaipur or Udaipur. It is also a great city to do a village tour, an opportunity you might not get in larger cities like Udaipur and Jaipur.
Check at the fort if any heritage tours are available. If you have time, Jodhpur is an especially good place from which to take a camel safari into the desert.