Celebrity Jessica Biel & Emile Hirsch's Mountain-Climbing Expedition! Relive the Summit on the Summit climb as they scale Mt. Kilimanjaro for a worthy cause By People Staff Updated on December 22, 2021 06:14 PM Share Tweet Pin Email Trending Videos 01 of 05 STARS TREK Summit on the Summit What a way to kick off 2010! A star-studded group of actors, musicians and activists band together on Jan. 7 to begin their ascent to the top of Mt. Kilimanjaro, Africa's tallest peak at 19,340 feet, to raise awareness and funds for the global water crisis. Included in the Summit on the Summit expedition: actress Jessica Biel, Into the Wild star Emile Hirsch, the granddaughters of iconic ocean explorer Jacques Cousteau and Robert F. Kennedy, and Grammy-nominated musician Kenna, the Ethiopian-born founder of the initiative. 02 of 05 PEAK CONDITIONING Travis Miller The climbers – including (from left) UN Foundation executive Elizabeth Gore, Jessica Biel, rapper Lupe Fiasco and Transformers actress Isabel Lucas – endure rain and even a blizzard while putting in daily seven-hour hikes. Despite the conditions, Biel is "kicking butt," says Gore. "She's doing just great. She and I are throwing jokes at each other back and forth every 10 steps." 03 of 05 ROUGHING IT Michael Muller As the climbers get closer to the Mt. Kilimanjaro summit, many experience headaches and stomach problems because of the high altitudes. But there's no turning back. "It's pretty kick ass that all of the climbers have made it all the way," says Gore. "We're all trying to help each other get to the top." 04 of 05 HIGH SPIRITS Michael Muller While the climb has been arduous, the group manages to have some fun during their down time. "We've played every game you can imagine – travel Scrabble, word games. And there is a lot of free-style rapping going on," says Gore. 05 of 05 FINAL DESTINATION Michael Muller Look what a little team effort pulled off! On Jan. 12, the sixth and final day of their expedition, the Summit group snaps a photo from Mt. Kilimanjaro's Uhuru Peak holding a sign reading "SEND WATER." "The last 48 hours have been the most intense and physically grueling experience of my life," says Hirsch. "Miraculously, we all made it to the top together." To see more photos, videos and Tweets from the expedition, visit www.summitonthesummit.com.