Mount Yuntai, also known as Yuntaishan, is the highest point of Nangan Island in the Matsu archipelago. Rising 248 meters above sea level, this peak serves not only as a magnificent observation deck but also as an important historical monument reflecting the military heritage for which Taiwan is known. For a long time, the mountain was a restricted strategic site, and it was only in 2010 that access was opened to the general public.

The main architectural landmark of the summit is the military intelligence building, which today functions as a museum. From its platforms, visitors can enjoy breathtaking panoramic views of the neighboring islands and the endless sea, making it a must-visit for nature landscape enthusiasts. The site is included in a national scenic area where the region's pristine ecosystem is carefully preserved.
In addition to its historical value, Yuntaishan attracts ecotourism lovers. The surrounding untouched forests are home to rare bird species, including the famous Chinese crested terns. The combination of the rugged aesthetics of military fortifications and the fragile beauty of wild nature creates a unique atmosphere highly valued by travelers from all over the world.