This task is about reading the given passage and construct a question about the information present in the passage. Construct a question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) its answer is a continuous text span from the paragraph. Avoid creating questions that (i) can be answered correctly without actually understanding the paragraph and (ii) uses same words or phrases given in the passage.
Q: The rulers of the expansionist Qin dynasty, based in present-day Gansu and Shaanxi, were only the first strategists to realize that the area's military importance matched its commercial and agricultural significance. The Sichuan basin is surrounded by the Himalayas to the west, the Qin Mountains to the north, and mountainous areas of Yunnan to the south. Since the Yangtze flows through the basin and then through the perilous Yangzi Gorges to eastern and southern China, Sichuan was a staging area for amphibious military forces and a refuge for political refugees.[citation needed]
A:
What surrounds the Sichuan basin to the west?