Adam's Bridge, also known as Ram Setu, is a limestone shoal chain between Pamban Island (Rameswaram) and Mannar Island (Sri Lanka). Dhanushkodi, at the tip of Pamban Island, is where the bridge remnants are most visible and accessible, making it the correct answer. Ramanathapuram is a district, Rameswaram is the main town, and Ramanagar is not related.