Walking a fine line

Slacklining, which originated in the United States when rock climbers looked for ways to hone their skills, is today a growing sport in China. Zhang Zefeng reports.

On a sunny morning, Zhang Liang gazes into the distance while perched barefoot on a 100-meter-long rope that is strung between two green camphor trees under a busy Shanghai urban viaduct.

Zhang calls the place an "urban forest". He stands up, wobbles back and forth without falling.