Sangdui La: Driving the high-altitude military frontier at 5,103m

Just a stone's throw east of Siyaba La, you'll find Sangdui La, a border-straddling beast of a pass that tops out at a whopping 5,103m (16,742ft)! Perched right on the edge between Nepal's Mustang District and Tibet, China, it's deep in the Himalayas and part of a pretty sensitive military zone. Definitely one of the highest roads around.

Forget civilian traffic; this is strictly a military road used for border patrols and keeping an eye on things from way up high. It's a "ghost road" for us overlanders, the kind you see on maps but can only dream of driving.

Think brutal high-altitude desert driving. We're talking loose scree, volcanic dust, and weathered rock – all unpaved. Above 5,100 meters, even the toughest 4x4 is going to struggle. Engines lose power with the lack of oxygen, and cooling systems get pushed to the absolute limit in the thin, dry air. Only heavy-duty military vehicles can handle the steep climbs and the ruts carved out by melting snow.

You'll only find this pass accessible in the summer, and even then, briefly. The rest of the year, it's buried under snow and battered by crazy winds. And forget about facilities – there's nothing. No fuel, no shelter, no medical aid. Breaking down up here could be deadly, as the nearest settlement is a long trek away through some seriously unforgiving terrain.

Like Siyaba La, Sangdui La is part of a defensive line, watched over by Chinese border guards. The summit is often fortified, keeping an eye on the vast Tibetan plateau to the north and the valleys of Mustang to the south. For those exploring Upper Mustang, these passes mark a hard stop. The road ends at military checkpoints.

While the idea of reaching such a height is tempting, Sangdui La is all about isolation and surveillance. It's a reminder of the Himalayas' raw power, where geography and politics meet to create routes that are off-limits to most. If you're in the area, respect the signs. Getting too close without permission could mean trouble with the border authorities.