VPR/Patti Daniels

Jake Lahne, left, belays Chris Corcoran as he begins a climb, while another climber looks on.

It's Wednesday and time for Summer School! Our weekly lesson in fun activities, skills and hobbies to make the most of summer. Today we head to the gym -- that is, the indoor rock climbing gym, to learn basics of scaling a wall.

At Petra Cliffs Climbing Center & Mountaineering School in Burlington the floor is covered with thick rubber mats, and that's reassuring. Around the cavernous space pairs of climbers are connected to each other by long ropes, and by a desire to climb. We asked Chris Corcoran and Kane Lahne to tell of the basics of indoor top-rope climbing.