ascend ascending coil constrain constrict focus focused snail spiral stair staircase tunnel twist twisted climbing man rappel striving UP activities artificial artificial structure belayer belaying climb climber climbing harness climbing rope climbing technique climbing wall descend descending equipment girl give outdoor sport portable wall safety safety harness shaped climbing holds sport structure surface take Tension youth boy helmet indoor sport rock climbing shoes ascent difficult difficulty hard landscape madeira mount mountain natural nature rock rocky steep architecture brick elements England english flagstones garden Great Britain stairs steps blue sky cold feet follow footprints footsteps hill prints snow trail white winter