Visit Long Son Pagoda and climb to the big white Buddha statue

Beach day — rent a lounger or just use your towel on the public beach

Explore Nha Trang Night Market for seafood and souvenirs

Take a mud bath at Thap Ba Hot Spring or I-Resort (~$8–15)

Get PADI certified — Open Water courses from ~$250 at dive shops like Sailing Club Divers or Vietnam Active