Starting from Nanjing with the theme of "soaking in hot springs", take an autumn trip to Yangzhou. In recent years, the popularity of hot springs in Yangzhou has skyrocketed, earning it the label of "City of Hot Springs". Taking off the robe of an economic center and putting on the silk scarf of "leisure tourism", Yangzhou suddenly had a clear and beautiful image, just the kind that Jiren Jun liked.

At the end of the last century, with the geological classification of "Yashan" in Yangzhou as a volcano, and the discovery of Yangzhou's unique geothermal resources, multiple geothermal wells were drilled with temperatures exceeding 70 ℃. Hot springs promoted the transformation and upgrading of the tourism industry and served medical care, planting and breeding, with significant effects. And as an extremely rare volcanic geology in Jiangsu, Naishan has become an excellent place for geographical study tours. The first stop of the hot spring journey is to visit Mount Nai and decipher the underground code of the hot spring city.

Located in the northwest of Yangzhou, adjacent to the Liuhe District of Nanjing, Naishan is an unremarkable twin peak mountain with an area of only 1 square kilometer. If it weren't for deliberately locking in Yashan as the destination, it's likely to have been missed. However, 10 million years back in time, Naishan is an iconic highland along the coast of East China. Its mountain has been buried by continuously spewing magma, and now only remains as a volcanic crater, covered in green vegetation that looks flat and unremarkable to the eye.

Approaching Mount Na, it was discovered that the primitive landform had developed into radial valleys, and the surrounding sedimentary strata were inclined towards the mountain. Its volcanic eruption facies conglomerate, breccia lava, and volcanic sedimentary facies tuff were all distributed in a circular pattern around the volcanic channel facies olivine basalt, forming a typical shield volcano.

The Na Mountain is covered with stone pillars, forests, and peaks, in various shapes and sizes, with a grand scale and majestic momentum. Its value is not only on the geological scale, but also as a landscape and garden stone for appreciation, which is a new highlight of local tourism elements. The stone pillars are named according to their different forms: Lusheng Peak, Shipai Peak, Wuzhi Peak, and Shizhu Waterfall. Among them, one type of curved stone pillar is the most peculiar, resembling a hornet's nest hanging on a mountain slope, called "Bundled Stone Slope".

In the 21st century, the geological community surveyed the top 10 volcanic rock column landscapes in the world, with bundled rock slopes being one of them. The other 9 attractions are "The Great Stone Road in Northern Ireland, the Hong Kong Saigon Yellow Stone Pillar, the Syrian Golan Heights Hexagonal Pool, the Italian Giant Island, the Devil's Tower in Wyoming, the Skaftafeld Waterfall in Iceland, the Devil's Rock Pillars in California, the Fingal Cave in Scotland, and the artificial wall in Jeju Island, South Korea".

The cross-section of the columnar joints in Naishan is mostly an equilateral pentagon or quadrilateral, with few hexagons. This is because when magma cools, countless condensation and contraction centers are formed on the surface, which are arranged equally and have a perfect geometric shape, like deliberately chiseled by a stonemason. The color of these volcanic rocks has weathered to white on the columnar planes and black on the cross-sections, making their scale and integrity very rare.

Due to the well preserved shield shaped mountain body and rich geological relics landscape, it has important scientific and popular science significance for in-depth research on the evolution of basic volcanic eruptions, the genesis of columnar joints, the structural effects of structural joints on the stress field of mountain climbing mechanisms, the generation relationship between ancient Yangtze River evolution and basalt rock columns, and the stratigraphic relationship between mammalian and reptile fossils.

As a rare volcanic wonder, the most effective way to develop and protect Mount Na is to establish a geological park, while also protecting rare groups of wood and ossified stones both domestically and internationally. It is not only the focus of geological research in East China, but also a geography practical course for study tours.

The software and hardware facilities in the park are complete, and there are elegant cafes along the scenic spots. Here, you can easily read and understand the passage of time.

10 million years vs. 100 years. Wandering among the dense stone pillars for a long time, thinking about how human life fleeting in front of the pillars, like a speck of dust.

After strolling through the mountains, the family also got their dream of soaking in hot springs that evening. Volcanoes and geothermal energy are like "twin brothers". Although Mount Nai is an extinct volcano, its never cooling exhalation can still be felt through the misty water vapor.

It has always been strange that places with volcanoes in the world are also places where humans like to live. Yangzhou was lively in Chinese history for 2000 years, and it was thought that it would cool down after losing its advantage as a transportation hub. However, due to the volcanoes, the heat still persists.