One hundred and twenty five bike riders sped off alongside the walls of the Old City to the squeak of a 13-year-old's shofar blast on a cool Jerusalem morning. As we snaked past Jaffa Gate, I was struck by two things. The first was the almost magical sensation of cycling around all this ancient beauty. The second was how these hills on which I'd trained for this trip were nothing compared to what lay ahead. Six days and 290 miles later, the fourth annual Arava Institute Hazon Israel Ride ended with a precipitous descent into Eilat. The ride is the brainchild of David Lehrer, director of the Arava Institute for Environmental Studies at Kibbutz Ketura; Howie Rodenstein, Israel Ride Chair; and Nigel Savage, executive director of Hazon. Six years ago, they came up with the idea to combine an outdoor activity with environmental education and fundraising - and the Ride was born. Since then, it has mushroomed annually, from an initial 30 participants to 125, and raises several hundred thousand dollars a year. The Institute has a dual strategy. During its 10 years in existence, it has striven to educate young adults to become environmentalists. At the same time, it has attempted to promote regional cooperation by recruiting students from all over. Jordanians, Palestinians and North Americans come to Kibbutz Ketura, which was carved out of the desert just north of Eilat some 35 years ago, to learn and discuss environmental and other issues with their Israeli counterparts. Lehrer says he hopes that "someday the environment ministers of Israel, Jordan and the Palestinian Authority will all be graduates of the Institute." PROPELLING YOURSELF from Jerusalem to Eilat with your own two legs really changes your perspective. I saw the southern part of Israel unfold before my eyes, at times in a seemingly unending wave of barren, daunting desert, at others in a breathtaking hue I hadn't previously encountered. And when I reached the southernmost tip of of the country, I felt that it had revolutionized my sense of what my body could handle. The youngest member of our group was 12 - the daughter of Institute founder and Adam Teva V'Din lobbyist Alon Tal. The eldest was 69. I, who am 28 and in decent physical shape, can honestly say it was the hardest physical challenge I have ever undertaken. Yet, as I discovered to my shock, another cyclist in our group had had a pacemaker installed 10 years ago. "When I couldn't make it up some of the hills without taking a break," he said, "I would pull over, wait for my heart to settle down, remount and continue." WHILE BICYCLING was certainly a major component of the trip - 10 hours of pedalling a day can hardly be considered insignificant - the environmental aspect was no less significant. For example, one of our stops was at an observation point from which we could see Ashkelon to the right and Gaza to the left. Directly below us was a Jewish National Fund reservoir. According to a retired IDF commander who served in Gaza in the mid-90s and who is now active in JNF activities, the JNF has been building reservoirs all over the country to help alleviate its water shortage. "Ashkelon boasts Israel's first desalination plant," Tal pointed out. "It produces water that is even tastier than that of the Kinneret, because it doesn't have the same high mineral content." Ashkelon, noted Tal, is also home to sewage treatment plants. Sixty-six percent of the country's waste is recycled for agricultural use. It is put through the treatment plant and then funneled to fields throughout the Negev. "At UN environmental committee meetings, officials from African countries frequently approach me about water-use questions," Tal said. Two full days of riding later, we visited Machtesh Ramon (the Ramon Crater), with a spectacular view from above and a terrifying descent below - on a kilometers-long narrow, winding road which forced us to slow down drastically so as not to fly off the edge. Just before reaching the end, however, the road straightened out and the wind whipped through my helmet as I raced into the multi-colored machtesh, which, incidentally, is the official word used internationally for this specific kind of geological formation. After crossing the crater, we entered an area of the Negev inhabited mainly by Beduin and used by Israel for military training. Here we passed many tank crews who were no doubt wondering how we could be so daft as to be riding bikes in 40-degree weather. Every once in a while, fighter planes would zoom over our heads, making our pace seem especially slow, since it took them about 15 seconds to cover territory that we spent hours crossing. NOW, IF you travel through this area by car - with your air-conditioning blasting and radio blaring - you'll probably miss this phenomenon, but there's a palpable change that comes over you down here. Suddenly, the sky seems infinite, the landscape a limitless series of rolling hills, and the heat is intense beyond belief. It makes you feel small and overwhelmed. As I watched a Beduin on a donkey pass by several hundred meters to my left, I wanted to pull over and stop. But I didn't. Instead, I looked back for my friend, David - who was huffing and puffing behind me - and waited for him to catch up. We were like two insignificant specks in an ancient land and landscape. We kept one another company - and reassured - by talking and telling jokes. At the end of that grueling day - the hardest of the entire journey - we finally arrived at our destination: a patch of green in the wilderness, Kibbutz Ketura. At the Institute, we met some of the students, each of whose time there involves the undertaking of an individual project. As part of her MA in Environmental Studies, for example, Ilana Meallem, an immigrant from England, lived in a Beduin village for seven months to study how the villagers manage their solid waste disposal. What she discovered was the result of the lack of any official garbage disposal in those villages not recognized by the state: These villages handle their garbage by burning it in trenches they dig behind their houses. Burning garbage, Meallem explained, releases toxic chemicals into the air which the Beduin then have no alternative but to inhale. She showed us photos of children playing next to burning mounds of garbage because they don't know any better. Thanks to Meallem's first-hand research, this problem has been exposed - which hopefully will lead to a safer solution for these Beduin. It is stories like this that I took away with me from the journey, along with the feeling of physical accomplishment. There is no question that the trip changed my life in ways that I can't even yet fully determine, since it's only been two weeks since the adventure. But whenever I turn on a faucet or flush a toilet, I'll feel a little better knowing that the water will be recycled, and that somewhere deep in the Arava there are people who have dedicated their lives to making sure we and our descendants have the natural resources so sorely needed and so easily taken for granted.