Although you won't find any discounts at the national parks, most museums and other attractions around South America do offer discounts for students. It always pays to ask.
The International Student Travel Confederation (ISTC; www.istc.org) was formed in 1949 to make travel around the world more affordable for students. Check out its website for comprehensive travel services information and details on how to get an International Student Identity Card (ISIC), which qualifies students for substantial savings on rail passes, plane tickets, entrance fees, and more. It also provides students with basic health and life insurance and a 24-hour help line. The card is valid for a maximum of 18 months. You can apply for the card online or in person at STA Travel (tel. 800/781-4040 in North America; www.statravel.com), the biggest student travel agency in the world; check out the website to locate STA Travel offices worldwide.
If you're no longer a student but are still 25 or younger, you can get an International Youth Travel Card (IYTC) from the same people, which entitles you to some discounts. Travel CUTS (tel. 800/592-2887; www.travelcuts.com) offers similar services for both Canadians and U.S. residents. Irish students may prefer to turn to USIT (tel. 01/602-1904; www.usit.ie), an Ireland-based specialist in student, youth, and independent travel.
Note: This information was accurate when it was published, but can change without notice. Please be sure to confirm all rates and details directly with the companies in question before planning your trip.