Bethlehem, PA Outdoor Activities

When Brian McInerney reflects on the humble beginnings of Wheel Fun Rentals, he points to his childhood passion for bikes. "As far back as I can remember, I had a real love affair with bicycles," he recalls. During a trip to Italy in 1987, Brian's affinity for cycling blossomed into a full-fledged obsession when he spotted locals' transporter of choice, the surrey. Inspired, he began importing the Italian four-wheelers to a rental business in the U.S. that eventually expanded into Wheel Fun Rentals, now a nationwide web of shops that also loans out bikes, electric cars and mopeds, and man-powered watercraft. Atop bicycles and surreys built for solo riders or entire families, patrons embark on self-guided tours of major U.S. cities. Led by maps and lists of nearby sites of historical or cultural significance, riders zoom down bike paths and safe, lightly trafficked streets. Adventuresome athletes can also compete in activities such as surrey scavenger hunts and blindfold obstacle courses navigated via shouted instructions from a seeing teammate or exceptionally long rounds of trial and error.

Competitors in the Professional Indoor Football League's United Conference since 2011, the Steelhawks prey on the opposition across the 50-yard pitch inside Stabler Arena. With a roster of gridiron stars, many of which were standouts at colleges across the country, the Steelhawks bring a fast-paced style of play to a football-crazed fanbase. The Steelhawks' mascot, Talon, regales fans in the stands during games with signature cheers and seminars on how to build structurally sound nests.

Lehigh Valley Grand Prix's gas-powered Sodi GT5 Proline karts zip around a quarter-mile racetrack with 11 brake-stomping turns. The karts feature air-intake units that trap their exhaust and keep the atmosphere fresh, and the track—constructed from 1,300 used Goodyear tires and the shredded remains of Mario Andretti's learner's permit—is outfitted with three observation platforms for track marshals to regulate each lap and guarantee riders' safety. A full-time mechanic keeps finish lines crowded by calibrating karts to run within three-tenths of a second of one another and hanging hundreds of piñatas from the checkered flag. At the facility's bar, Octane, drivers can refuel with drinks and food while watching stock-car races on the five 42-inch TVs.

The ECHL affiliate of the Philadelphia Flyers, the Trenton Titans compete against the country's top hockey prospects in the Atlantic Division of the league's Eastern Conference. Founded in 1999, the Titans won the Kelly Cup in 2005 behind captain Rick Kowalsky and leading-scorer Scott Bertoli, capping off an impressive six-year span in which the team missed the playoffs only one time. As the Titans continue their quest to replicate past glory, raucous fans clad in red cheer them on at Sun National Bank Center, aided by the team mascot Rivet, who energizes fans without throwing AA batteries into the stands.

More than 12,000 square feet of indoor rock-climbing surfaces greet climbers at Doylestown Rock Gym, where they can test their scaling acumen on a network of bulges, overhangs, chimneys, and cracks. As climbers scramble over the massive facility, an alert staffer remains ready to assist when needed and remind nervous beginners that there are no mountain lions around. The space presents suitable challenges for all skill levels and facilitates advancement in the sport through individual and group instruction by on-staff experts.

At any given moment, 150,000 gallons of water are churning through CoCo Key Water Resort, fueling the nearly 1,000 feet of water slides weaving through the 55,000-square-foot indoor water park attached to the Hotel ML. On the slide Shark Slam, patrons plummet four stories, and on the Dip-In Theater little ones gently glide into a one-foot wading pool. Kids of all ages scale Parrot's Perch, firing water cannons across the colorful jungle gym and drenching playmates with buckets of water. Adults can take a relaxing approach to their day at the park and drift down the 300-foot lazy river or soak in the kid-free indoor and outdoor whirlpools.

Out of the water, the play-till-you-win Key Quest Arcade guarantees each gamer a victory on high-profile games, such as Guitar Hero and Dance Dance Revolution. The water park also houses three on-site eateries and a full-service bar.