Rong May Glass Bridge

4.2 centimeters.

That is all, about the width of two adult fingers held together. It is the thickness of the glass between a visitor's feet and the open sky below. Under that glass there is no ground and no slab of stone holding anything up. There is only wind, drifting cloud, and the earth far below, about 300 meters down.

This is the Rồng Mây Glass Bridge, clinging to a cliff at the top of the Ô Quy Hồ Pass. It is in Lai Châu Province, about 2,200 meters above sea level. When the bridge opened on November 16, 2019, it became the highest glass bridge in Vietnam.

Before it, the whole country had only one glass bridge. It spanned the Dải Yếm waterfall on the Mộc Châu plateau, 22 meters high. That is about as tall as a seven-story building. The elevator that carries visitors up to the bridge is 300 meters tall on its own. Stood beside a building, it would reach roughly 100 stories.

But the trip up to the bridge does not begin high in the air. It begins inside the mountain.

A passage leads deep into the rock, and at its end the elevator is waiting. Each trip carries 30 people. The car has three transparent sides, yet for the first 80 meters the only thing behind the glass is the rock wall. The stone slides past right beside the car, gray and silent, sinking slowly as the elevator rises. Inside, everyone falls quiet without meaning to, and waits.

Then the elevator breaks out of the mountain. Light floods in all at once. The rock wall disappears, and in its place is a vast stretch of sky, mountains piled on mountains, green, then blue, then fading into cloud. This is the Hoàng Liên Sơn range. The elevator keeps climbing, on and on, until its doors open right at the head of the bridge.

The bridge juts straight out from the cliff for 60 meters. The cliff is sandstone of the Hoàng Liên Sơn range, and the bridge was built out from that very rock face. The floor is glass, and glass walls run along both sides of the walkway. Below is the abyss. To either side are mountains. Ahead there is only wind and cloud.

The first step onto the glass is always the hardest. The eyes say there is nothing underneath. The feet feel a floor that is hard and solid. Some people step very slowly, gripping the hand of someone they love. A small child, though, may want to crouch right down and press their face to the glass, to get a good look at the deep drop below.

What keeps those steps steady is that same 4.2 centimeters. The deck is made of three layers of tempered glass, bonded tightly with four layers of bulletproof film. The whole structure can bear the weight of 3,000 people at once. Even so, when the bridge first opened, no more than 500 visitors were allowed on it at a time, to keep a generous margin of safety.

Stand in the middle of the bridge and turn around, and the Ô Quy Hồ Pass winds across the mountainside like a ribbon of silk. People of the northwest still call it the "King of Passes". It is one of the four great mountain passes of the region, about 50 kilometers long. It crosses the range between Lào Cai and Lai Châu. Sa Pa lies only about 17 kilometers from here.

At this height, the clouds are the closest neighbors. On some days the whole bridge sinks into a sea of cloud. Anyone standing on the glass then sees no drop below, only a thick white layer, soft as cotton, rolling slowly underfoot. On clear days, the Hoàng Liên Sơn range shows itself ridge by ridge. Summers up here are cool and fresh, no less so than in Sa Pa or Da Lat.

On the way up to the upper area there is also a flight of steps painted in many bright colors. It carries a sweet name: the "Rainbow of Love". Climbing it step by step feels like walking up a rainbow standing upright among the mountains.

The bridge also has a small story of its own. In early February 2022, visitors photographed a glass panel on the bridge with a crack in it and tiny shards of glass around it. The pictures spread online. Just two days later, a provincial inspection team arrived on site. The team concluded that the panel had been made to look cracked and placed near the elevator frame to give visitors an extra thrill. Even so, the team still required a new panel to be fitted.

But replacing glass at the top of a mountain pass in mid-February is no easy task. Ice covered the Ô Quy Hồ Pass, and the work had to wait for the sun to come out. Only on the evening of February 23 did the new panel settle into place. It measured about one square meter and was also made of three layers. No one was hurt at any point. The old cracked panel was kept for display, and it would never again be fitted anywhere on the bridge.

The elevator through the mountain and the glass bridge hanging in the sky are the two reasons people come all the way up to the top of the pass.

As evening falls, the sunlight slants toward the distant ranges. Some young people come up here just to stand on the bridge and wait for sunset. The late light on the pass grows soft and calm, laying a warm color over each layer of mountains.

Look down through those 4.2 centimeters of glass then, and the abyss is still there, the clouds still drifting. But the feet have grown used to it. A gentle wind slips through the glass walls, and the Hoàng Liên Sơn range lies still ahead, quietly waiting for the next footstep.