Gwalior is one of central India's great fortress cities, dominated by a long sandstone ridge that rises abruptly above the plain. The fort is visible from half the city and still feels like the place's organising fact: palaces, temples, Jain carvings and ramparts all sit on or around that dramatic slab of rock.
The essential visit is Gwalior Fort. Inside and around it are the tiled Man Mandir Palace, the hybrid Teli ka Mandir, the delicately carved Sasbahu Temples, and the rock-cut Jain figures of Gopachal Parvat. Down in the city, Jai Vilas Palace shows the Scindia dynasty in full 19th-century European flourish.
Gwalior is busy, dusty and not as tourist-softened as Rajasthan's famous fort towns. That is part of the attraction. You get major monuments without the same level of performance around them, and the city works well as a stop between Agra, Datia, Orchha and Khajuraho. Give it at least one full day; two is better if you want to see the fort slowly and still have time for music history around Tansen's tomb.