Efron, 25, posted the photo of himself on the mountain flanked by the ruins of Machu Picchu on Instagram Friday, People magazine reported.
"Hey guys! Just returned from an incredible trip to Peru with my dad and wanted to thank you all for your support these past few weeks ... means the world to me. Love you guys!" he wrote in the post.
Efron entered rehab last spring for substance abuse, but is now "doing great," a source told People.com last week.
"He's healthy, happy and not drinking," an insider told E! News.
Efron is best known for his roles in the "High School Musical" franchise and the movie musical "Hairspray." He will soon be seen in the big-screen drama "Parkland."