Located about 15 km southeast of Sai Kung Town Centre, the Ninepin Group comprises South Ninepin Island, North Ninepin Island and East Ninepin Island, along with several small rock islets. It is located in the open sea and is thus subject to the relentless impact of strong wind and waves, resulting in diverse peculiar coastal landforms, including steep cliffs, sea arches and various strangely-shaped rocks. Famous scenic wonders on North Ninepin Island include Cannon Rock, Moon Rocks and Big Stove Arch; and on South Ninepin Island include Stone Arch, Jacob's Ladder Cave, Backwash Cave and Y-shaped Cave. In the Sai Kung Volcanic Rock Region, the hexagonal rock columns exposed on North Ninepin are the most magnificent. The columns may have a diameter of over 2 m, making them the largest in the area. As the Ninepin Group is within the core protection area, and in view of the strong wind, big waves and dangerous terrain, sightseeing is suitable only on calm summer days, and only boat tours with no land excursion.
The name "Ninepin" is inspired by an old British game similar to modern day bowling. When British seamen first saw the array of these islands, the familiar bowling game sprang to mind and they gave the group this colourful name. The Chinese name Guo Chau, meaning fruit island, is even more innovative. It is said that the Ninepin Group (Kwo Chau Islands) was originally called Guo Pun Chau which means fruit platter. It is so named because viewed from above, the group looks like scattered fruit from an overturned platter from heaven.
The Ninepin Group is made up of North Ninepin Island, South Ninepin Island, East Ninepin Island and other islets. North Ninepin includes Sai Mei Chau and Hok Tsai Pai. South Ninepin includes Tai Chau, Tai Chau Mei, Ta Long Pai and Lai Chi Pai. East Ninepin includes Tuen Chau Mei, Shue Long Chau and Lung Shuen Pai.
Riding on a small boat to South Ninepin Island, the sea is calm and beryl. After going ashore, the first thing that comes to view is the imposing "Tiger Mouth Cave". Hong Kong's eastern coast has its fair share of famous caves, and this is one of them. In geology, this "cave" is actually a sea arch. Hong Kong is influenced by easterly wind most part of the year. The islands east of Sai Kung and Clearwater Bay peninsula are completely exposed to this natural force. Even though volcanic rocks are essentially hard and resistant, wind and waves have taken their toll over the ages. The resultant terrain is rugged and imposing. Given such challenging condition, visitors to the Ninepins can only get ashore during two or three summer months every year. Standing below the giant arch, one will marvel at nature's brilliant craftsmanship and truly appreciate the greatness of nature's power relative to our own.