When they say multisport, they mean it. You can pick from a combination of swimming, biking, and running. No need to do a triathlon (this one’s a 1K swim, 30K bike, and 7.4k run) or half marathon, although they have those, You can also do a duathlon (run, bike, run), an aquabike (swim, bike,) or a 5K run. The courses are flat, so expect fast times. The whole seaside town gets involved: The transition area is on the main street, and when you cross the finish line, you can party on the boardwalk. September 20 to 22; bethanybeachtri.com In 1904, auto manufacturers showcased their “horseless carriages” on a steep hill on Mount Washington. (Mercedes won.) Today, 635 people line up annually to do the climb on two wheels. This 7.6-mile bike race is far steeper than what you see in the Tour de France. The average grade is 12 percent, with extended sections of 18 percent, capped off by a 22 percent grade for the last 50 yards. It’s considered the toughest paved-hill climb in the world. August 15; mwarbh.org The growing-in-the-U. S. sport of Swim Run should probably be called Swim Run Swim Run, because you do each more than once. In Casco Bay, you swim among seals in 60-degree water...