VinWonders (formerly Vinpearl Land) is a large theme park and resort complex on Hon Tre island, reached by a cable car from the Nha Trang mainland. The cable car crossing — 3.3 km over the bay, with views of the city and the surrounding islands — is itself a highlight, even if you do not want to spend the day at the park.
The complex includes a water park, an amusement park, an aquarium, and various entertainment venues. It is popular with Vietnamese families and tour groups, less so with independent Western travelers. The prices are substantial by Vietnamese standards. Whether it is worth visiting depends on your appetite for theme park infrastructure; the island setting is genuinely beautiful.