Cataract Canyon ... the park’s 300-million-year-old rock walls, which are impassable by foot. The river ride delivers smooth, floatable stretches intermixed with rowdy Class III-IV whitewater.

TINLEY PARK, IL — Village flags will be at half-staff, and the Village of Tinley Park on Wednesday will host a ceremony to mark the 23rd anniversary of the Sept. 11, 2001 terrorist attacks.