Down to Earth with Zac Efron

E1. Iceland

In between getting an up-close look at Iceland's renewable energy efforts, Zac soaks in a spa with Darin, samples reindeer and views natural wonders.

★ 8.8

E2. France

Before heading to Paris to learn about its tap water system, Zac joins pal Anna Kendrick for a lesson in H20, courtesy of a water sommelier in LA.

★ 8.5

E3. Costa Rica

Zac and Darin try out life at a swanky eco-village committed to a small environmental footprint, visit a wildlife refuge and enjoy a zip lining trip.

★ 8.2

E4. Sardinia

On an island that boasts a notable number of centenarians, Zac rethinks his view on nutrition as he ponders how the locals live such long, healthy lives.

★ 8.2

E5. Lima

Following a crash course in apple growing, Zac and Darin head to Peru to delve into potato cryopreservation, biopiracy and the sport of sandboarding.

★ 8.5

E6. Puerto Rico

In the devastating wake of Hurricane Maria, Zac explores sustainability in the region, where he meets chef José Andrés, milks a goat and eats ceviche.

★ 8.8