This awesome rock formation forms a natural water park once a year during the rainy season - allowing tourists to slide over the smooth rocks.

Video shows reveler Jirathiwat Boonbanlu letting himself be swept away by fast-flowing currents at the Tham Phra waterfall in Bueng Kan province, northeastern Thailand, on June 7.

The gushing clear water carried him down the narrow channel and into a pool below. A second holidaymaker followed after him and pinballed along the stream's rocky walls.

Jirathiwat said: 'The waterfall was very beautiful. It's amazing how the water flow down smoothly.'

The unique park forms at the peak of Thailand's annual rainy season in July and August when rain causes rivers to swell. The resulting waterfall makes a fun and safe slide for visitors to play on and swim in the natural pool below.

At other times of the year, the rocks are dry.