Ziplines originally were invented for just two functions: sneaking hamburgers over the Berlin Wall and zazzing up presidential entrances to State of the Union addresses. Discover function three and beyond with today's Groupon: for $25, you get two hours of treetop adventures with an instructional class and zipline tour at Seacoast Fun Park in Windham (up to a $53 value).

At Seacoast Fun Park, participants explore the treetops with more than 2,000 feet of ziplines and midair trails littered with more than 40 challenging obstacles and elements. After half-hour grounded-training sessions, guided tours escort gliding patrons down three diverse ziplines. Aerial forest-rope courses comprise five separate trails of varying difficulty for ape impersonators of all experience levels. Climbers traverse moving bridges and cargo nets, swing down a 900-foot zipline, and fling themselves through midair jumps. Sessions start every half hour, concluding with a final round beginning 2.5 hours before the park closes. Closed-toed shoes are required, and all clothing should be weather appropriate and worn tightly enough to avoid catching on ropes or sap that surrounding trees are conserving for their next pancake breakfast.