JAKARTA: In a working-class neighbourhood in North Jakarta, a group of children practise backflips and cartwheels, learning to stick their landings. If they take a tumble, there are no spring floors to cushion their fall, only two decrepit foam mats placed on unforgiving concrete. Their training ground is a rat-infested alley barely 2m wide, hemmed in by laundry racks and parked motorcycles. The children, aged six to 14, immediately pause their routine and lift the mats to make way for a motorcyclist. "This is what it's like training in an alley," Yoga, the founder of Indosalto Gymnastics Club, told CNA on a recent Saturday.