Beimen Sandbar Introduction
Penghu has two islets known as Tiezhanyu, named for their resemblance to an anvil. The northern Tiezhanyu, which belongs to Baisha Township, is located off the northwest coast of Penghu Island and is an uninhabited island predominantly formed by a basalt tableland, surrounded by steep sea cliffs. The lower layer of columnar basalt, made up of volcanic breccia, is relatively fragile. Due to the northeast monsoon, the northern shore has been eroded by ocean currents for a long time, forming a massive sea cave that small boats can enter. It is larger than the Blue Cave in Xijij Island, making it the largest sea cave in Penghu. Inside the cave, there is no sunlight, so the temperature is three to five degrees lower than outside, which is why it is also known as the “Air Conditioning Cave.” After arriving on the island, aside from the platform-like basalt, one can also see uniquely shaped honeycomb rocks and basalt joint grooves formed by water erosion, all characteristic of the northern Tiezhanyu's terrain. This area also once served as a military shooting range, leaving behind many iron scraps and rock fragments. Due to the short and shallow intertidal zone of northern Tiezhanyu and the lack of surrounding platforms, very few people come here, allowing thousands of birds to nest and inhabit the island. Among them, the most common is the Black-faced Spoonbill, which, when boats approach, emits warning calls and circles above in groups, as if reminding visitors that they are the true owners of this place!
