The city of Guilin lies amidst limestone towers and cones of different height and shape, on the alluvial plain of the Li river. This kind of landscape is called 'Fenglin' in Chinese which translates into a 'peak forest' and may be regarded as an equivalent of 'tower karst'. Shapes of individual hills are influenced by lithology and structure of the limestone. Most are developed within mechanically strong sparitic limestones whilst asymmetry is attributed to the inclination of bedding planes.
Elephant Trunk Hill, a karst tower c. 40 m high, is one of the most famous scenic spots in Guilin. It is located in the centre of the city and directly overlooks the river Li. Its major attraction is the Elephant Trunk Cave, a tunnel piercing through the flank of the hill in the level of the present-day valley floor. Higher above and to the left an entrance to another horizontal tunnel is seen which also goes through the hill. Multitude of cave horizons at different levels above the hill base is typical for karst towers around Guilin.
South-east of Guilin we observe a dramatic change in the landscape. The association of plains and isolated hills ('Fenglin') is replaced by closely spaced conical and domed hills reaching up to 500 m high. The intervening plains disappear; instead closed depressions (dolines) with floors at different altitudes separate neighbouring hills. This is the Chinese 'Fengcong' - 'peak cluster', that conforms with the characteristics of the closely set cone karst or polygonal karst. The river Li cuts through the 'Fengcong' between Guilin and Yangshuo forming a gorge which undoubtedly is one of seven geomorphological wonders of the world, and certainly one of the best sold Chinese tourist attractions.
The origin of the Li gorge is not fully understood. It seems that the gorge is antecedent and originated on the rising flank of the major syncline in the Late Tertiary and Quaternary. The entire boat trip down the river takes four hours and allows one to observe changing scenery, from 'Fenglin' through 'Fengcong' to a gently rolling landscape developed on sandstones, and then back to limestone towers at Yangshuo, at the end of the excursion.
The road from Guilin to Yangshuo goes across karstic corrosion plains (polje) surrounded by residual limestone towers. This photograph illustrates that the polje floor is underlain by strongly corroded limestone (foreground) and that in the slope development of karstic towers rockfalls play an important part. Parallel retreat of limestone hillslopes enables the poljes to extend laterally.
Close-up of one of the dolines within the 'peak cluster' karst, the 'Fengcong'. Alluvial sediments in the doline allow for cultivation.
Huangguoshu Falls are almost 80 m high and almost as that wide. The waterfall step is partly constructional. Massive tufa accumulation takes place on the step and also on the opposite side of the valley. The 'Curtain Cave' is a narrow gallery that goes behind tufa-covered drop of the waterfall. In the vicinity there are many more waterfalls of different drop and width making the area a 'waterfall country'.
Close to the Huangguoshu Falls is the Taixing Bridge where a 'stone forest' has been made accessible to the public. Individual limestone blocks and pillars are distinctly elongated and parallel to each other suggesting joint control. They probably developed as a covered karst, in the subsoil through strong selective corrosion of the limestone along the joints, and have been exposed relatively recently.
