The much-awaited longest and highest glass-bottomed bridge in the world opened to visitors over the weekend.

The bridge was opened in Saturday in a scene national park in central China’s Hunan province.

Spanning two cliffs in the Zhangjiajie Grand Canyon, the bridge is over one-quarter of a mile long and about 20 feet wide, hovering over a 1,000-foot vertical drop.

It looks from the air like a giant white butterfly.

For the sake of safety, the glass-bottomed bridge only receives 8,000 visitors per day at most. Visitors need to make appointments one day ahead, during the trial operation.

Paved with 99 panes of three-layered transparent glass, the bridge was completed last December at a cost of almost $3.5 million.

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