Geothermal Delights

Lying in a plain ringed by volcanoes and subject to frequent earth tremors, Tengchong is the capital of the most geophysically active county in Yunnan. One of the most magnificent of these volcanoes is Dayingshan, just ten km north of the city. Rising 2614 metres, and still active, it is easy to recognise by its cratered peak, of the kind that fits the classic image of a volcanic mountain. Dayingshan's last eruption was in 1609. Others in the vicinity look like they haven't erupted since their formation in the Cenozoic Era.

From Gongping, 20 km north of Tengchong, the land is studded with clusters of volcanoes, covering an area of 750 kmZ, over 13% of the county's territory. Some are not yet extinct and pumice stones and still lava streams decorate their slopes. No volcano has erupted in recent years, but as such events are unpredictable, that fact adds a tinge of excitement when hiking among them.

Besides the volcanoes, the county is famous for its 81 hot springs. The best group of these is Rehai, the Hot Sea, a collection of thermal springs and geysers 12 km northeast of Tengchong city, past rolling hills, picturesque villages and copses of pine and fir. Rehai is a park, becoming a resort, with hotels and restaurants in the front, marked trails to the major sites, and some of the hot springs contained in concrete vessels or engineered to flow into bath houses and pools. The star attraction is Dagunguo, Big Boiling Pot, over 6 metres in diameter, 1.5 metres deep, ringed by a guard rail, with a viewing platform nearby. In constant turbulence, it ejects puffs of steamy, vapourous clouds that waft up to the small temple above it and drift off against the dark green forest.

Rehai covers 9 kmZ and only a small part of it has been built up. Most of the springs and geysers have been left intact. Trails wind up and down the hills, with most sights on the right bank of the Zaotang River. From the Big Boiling Pot the trail descends to the swimming pool, passing several steaming springs and a couple of stone hot wells, with animal figures carved in low relief on the sides. Along the river bank, back towards the park entrance, steam rises from the ground on the right bank, between the stones on the left bank, and jets out of a fissure in a boulder every few seconds at the site called Spouting Toad's Mouth (Hamazui).

Nowhere else in Yunnan are hot springs and geysers concentrated in such a circumscribed area. Dehong Prefecture has 16, but most are in Lianghe, the next county south of Tengchong, and scattered over its territory.