After 13 days of Ayurvedic treatments, considering a beach: VARKALA or others

I’ll be in central KERALA (4 hours from KOCHI airport by car). For the rest of my stay, I’m planning to do "nothing" except brisk walking, Tai Chi... and swimming. The spot could be Varkala or somewhere else. If the place has nearby tourist sites like monuments, temples, or anything else, I’d be happy to let myself be guided. I’m traveling solo. GOA is a 7-hour drive away, or a flight, so I’d rather skip it (too far from KOCHI airport). This break will last a week, with a return to KOCHI airport. Thanks in advance for your ideas, experiences, and tips!