A short walk north from Anjuna brings you to the headland between Anjuna and Vagator beaches, crowned by the ruins of Chapora Fort. The Portuguese built it in 1717 on the site of an earlier Bijapur Sultanate fortification. There is no entry fee and most of the walls are still standing.
Climb up in the late afternoon. From the bastions you get a long view down both beaches, the Chapora River winding inland and the sun dropping into the Arabian Sea. It is one of the better sunset spots in north Goa, and gets correspondingly busy in season.