Udayagiri Fort crowns a steep hill about 80 km north of Nellore, its walls and bastions intact enough to give a clear sense of its former strength. The fort saw rulers from the Vijayanagara period through successive sultanates, the Portuguese, and eventually the British — each occupation left structural evidence in the form of different construction styles and modifications to the original walls.
The climb to the top is steep but manageable and takes about 30 minutes. The panoramic views over the surrounding plains make it worthwhile. Inside the fort walls there are several temples, granaries, and ruined palaces. The Udayagiri area has a cluster of other sites nearby; with a car you can combine it with a half-day trip.