Yolyn Am (Vulture's Mouth) was originally established to conserve the birdlife in the region, but it's now more famous for its dra-matic and very unusual scenery - it is a valley in the middle of the Gobi Desert, with metres-thick ice almost all year-round.

The small nature museum at the gate on the main road to Yolyn Am has a collection of dinosaur eggs and bones, stuffed birds and a snow leopard. There is also an ethnography museum in a ger, which is worth a visit.

Look out for the remarkable petrified wood lying by the roadside. The ranger office and museum sell some good souvenirs, including landscape paintings and, amaz-ingly, one of the best collections of Mongolian stamps in the country. 

From the museum, the road continues for another 10km to a car park. From there, a pleasant 25-minute walk, following the stream, leads to a gorge full of ice. In winter, the ice is up to 10m high, and continues down the gorge for another 10km. It remains frozen for most of the year, except lor about a month starting in late August.

You can walk on the ice - but be careful, especially in late summer.

The surrounding hills offer plenty of opportunities for some fine, if somewhat strenuous, day hikes. If you are lucky you might spot ibex or argali sheep along the steep valley ridges.

Mukhar Shiver. This location is very similar to Yolyn Am and it has been made into a protected area. As a result, entering the area by car is forbidden. Like Yolyn Am, it is frozen almost all year round and is surrounded by rocks.