Located just off the Nadi Main Street, you'll find the Nadi fresh produce markets which will give you a good taste of local life in Nadi even if you just have a couple of hours to spare. You can easily grab a taxi from Nadi airport and for around 10-15 Fiji dollars you can take in both the markets and the more general stores in the main street including the duty-free stores.
The Sri Siva Subramaniya temple
The Sri Siva Subramaniya temple is located at the southern end of the main road through Nadi and is the largest Hindu temple in the Southern Hemisphere. This is an hour well-spent if you're looking for a way to get a feel of the local Indian culture. Remember to dress modestly and be respectful as this is a place of worship. You aren't allowed to take any photographs inside the temple but you can take photos of the exterior.
Lunch and Shopping at Port Denarau
If you're looking for more international-quality shopping and dining in Nadi then your first stop should be Port Denarau. Port Denarau is open 7 days from 9am till 11pm (including school holidays) and is home to a collection of restaurants, bars, shopping, retail and clothing, tour operators, car rental agencies, as well as services such as spa, hair, nail and banks.