Morning: Start your day by watching the sunrise at the southernmost tip of India, Kanyakumari Beach. Visit the famous Vivekananda Rock Memorial, situated on a small island off the coast, accessible by a ferry ride.
Afternoon: Head over to the Thiruvalluvar Statue, a 133-feet tall stone statue of the poet and philosopher Thiruvalluvar. Then visit the Kanyakumari Temple, dedicated to the goddess Kumari Amman.
Evening: Catch the sunset at the Kanyakumari Beach and enjoy the street food available there.
Morning: Visit the famous Ramanathaswamy Temple, one of the twelve Jyotirlinga temples in India. Also, explore the exquisitely carved pillars and corridors of the temple.
Afternoon: Head over to Dhanushkodi, a ghost town devastated by a cyclone in 1964 and also the southernmost tip of Rameshwaram. Take a dip in the sea and enjoy the view of the Bay of Bengal and the Indian Ocean meeting there.
Evening: Visit the Pamban Bridge, which connects the Rameshwaram Island to the mainland. It is the longest sea bridge in India. Enjoy the sunset from the bridge and take a walk if possible.
In Kanyakumari, you can also visit the Padmanabhapuram Palace, a wooden palace of the Travancore dynasty. You should also check out the various water sports available at the Kanyakumari Beach.
If you have more time, you can extend your trip to Madurai, famous for the Meenakshi Temple, and also to Dindigul, famous for the Thalappakatti Biriyani. You can also consider visiting the Gulf of Mannar Marine National Park, famous for its coral reefs.
To maximize your fun, you can try a local cuisine, especially seafood, at restaurants near the locations mentioned above. You can also shop for local handicrafts and souvenirs at the local markets.
Don't forget to carry a water bottle, sunscreen, and a hat to beat the heat during your trip.