Wipeout on an untended waterbar and you’ll never take a maintained singletrack trail for granted again. Last year, volunteers at the International Mountain Biking Association’s 500 local clubs and chapters built 250 miles of brand new trail, wielding shovels, Pulaski’s, and come-alongs during single-day or weekend work parties across the country. Their sister organization, the American Hiking Society, hosted 65 different week-long trail building volunteer vacations from Hawaii to Maine. Every trip, including one to the Virgin Islands, includes meals and costs just $245. If you’ve got the coin, check out Conservation Volunteers International Program’s Machu Picchu trip. Their volunteers spend a week shoring up centuries-old stone walls inside the lost city or along the Inca Trail. You’ll stay nights just down the mountain at Aguas Calinetes, spend mornings with the work gloves on, and then each day when the hordes split at three to catch the train back to Cusco, you’ll have Machu Picchu to yourself. A little extra incentive: the $2,850 price tag is fully tax deductible.