Maoyu (Cat Islet) is administratively part of Wang'an Township, Penghu County. It is located approximately 16 kilometers southwest of Wang'an Islet and is named for its resemblance to two cats lying down on the sea when viewed from a distance. Currently an uninhabited island, Maoyu was historically used by the military and fishermen. The island consists of Large Maoyu, Small Maoyu, and several reefs, with a total land area of about 10 hectares. It reaches an elevation of 70 meters, making it the highest peak in the Penghu archipelago. The island's terrain is steep, surrounded by sheer cliffs on all sides. Large Maoyu is a massive rock formation that rises prominently above the water, towering over Small Maoyu, which lies to its east. At low tide, a 10-meter-wide channel separates the two islands, with a marine erosion platform on one side. The surrounding area is dotted with reefs, and the strong currents make it difficult for boats to approach or navigate. The upper layers of rock on Maoyu are composed of basalt with curved columnar joints, while the lower layers consist of volcanic breccia, giving the island a striking and unique volcanic geological landscape.
  
In 1991, the Penghu County Government designated Large Maoyu and Small Maoyu as the Maoyu Seabird Protection Zone, Penghu County under the Act on Wildlife Conservation, making it Taiwan's first wildlife protection area. The reserve covers both the 10-hectare landmass and extends 100 meters into the surrounding waters, with a total protected area of 36.2 hectares. Maoyu is home to a diverse array of bird species, with records indicating 45 to 55 species across more than 20 families. The brown noddy and bridled tern are the most common, accounting for 90% of the bird population. Maoyu is also the largest breeding site for brown noddies in Asia. During the breeding season from March to September, tens of thousands of seabirds flock here to nest and feed, creating a breathtaking spectacle. Other species, including the bridled tern, greater crested tern and black-naped tern, also breed on the island.
  
As Maoyu is a designated seabird protection zone, generally visitors are not allowed to set foot on the island. Sightseeing is limited to boat tours around the island and all forms of disturbance to seabirds or environmental destruction are strictly prohibited. Those who wish to land on the island for research purposes must obtain official approval. Although access to the islet is strictly controlled, during the summer breeding season, visitors can take boat trips to admire the seabirds from nearby waters.

Source: Penghu Travel