8 most beautiful sea arches in Hong Kong

Reachable by foot through trails that branch out from the MacLehose Trail or a 15-minute speedboat ride from the Sai Kung Pier, Pak Lap Wan (白腊灣) holds more than 200 years of fishing heritage. An adjacent bay further down served as a station for the navy of the Qing dynasty, where fleets sought shelter and food.

Tour the scenic coastline of Pak Lap Wan and alight yourself at Mok Min Cave (木棉洞; muk6 min4 dung6). The passageway under this beautiful sea arch winds through rocks and fissures and makes for a fun swim when water fills the cave. Besides feeling a pleasuring sensation in the water, you will encounter schools of coral fishes as sparkling waves toss themselves against the shore.

The Ninepin Islands is a group of jagged outcrops at the edge of the South China Sea, a lone and uninhabited landmass surrounded by water. Famous for its bulky hexagonal columns—with diameters over two metres—the secluded island has been battered by relentless winds and waves from the ocean.

As a result, many impressive landforms have found shapes here, including a sea arch sandwiched between inclined columnar slabs on the northeastern face of North Ninepin Island. Due to violent exposure to the sea on all of its sides and its irregular structure of hexagonal columns, it is only during summertime when small boats can make a safe landing here—making the island a highly seasonal destination.

Facing the South China Sea, Wang Chau (橫洲) is the smallest outcropped stratum of the Ung Kong Islands (甕缸群島; ung3 gong1 kwan4 dou2). Its sea arch—nicknamed the Moon Tooth Cave (月牙洞; jyut6 ngaa4 dung6)—plunges much deeper into the sea than its neighbouring arches on Bluff Island and Jin Island.

You can also explore its sea caves, including one that is especially popular with swimmers for its undulating passageway when the shoreline rises. To see the true grandeur of Mother Nature, some recommend visiting the island a few days after a typhoon when the sea surges with swirling waves whipping up a spectacular resonance. You can reach Moon Tooth Cave by joining a boat tour or guided kayak tour.

Jin Island—or Tiu Chung Chau (吊鐘洲; diu3 zung1 zau1)—is known for its hexagonal columns and pristine shallow waters. A popular destination for hiking and kayaking, the island features a beautiful sea arch apart from sea caves, rock pools, beaches, inlets, and hiking trails.

At the southern tip of the island lies a headland nicknamed the Goldfish Wagging Tail. Rated as the most beautiful of its kind in Hong Kong, you can kayak underneath its sea arch and take a dip in the shallow basin behind it. While there are no public ferries to Jin Island, you can join a boat tour from Sai Kung to reach the island.

Resembling a stretching turtle, Bluff Island is the second-largest island of the Ung Kong Group, featuring towering cliffs and hills covered by lush foliage that lazily transform into scenic, sandy beaches. Located on the southern shore of Bluff Island, Sha Tong Hau Cave (沙塘口洞; saa1 tong4 hau2 dung6) rises 25 metres above the shoreline as a narrow and rectangular-like opening puncturing the rocks. Admire the coastal view from your kayak or swim through the shaded passage on your back as you gaze up at gigantic granite prisms from the water below.

Basalt Island has some of the most dynamic geo-features amongst the Ung Kong Group. Its shores are outlined with sea caves, inlets, and basins of all kinds. On the southeastern shores, Lam Wan Kok Cave (欖灣角洞; laam5 waan1 gok3 dung6)—or the Guan Dao Cave (關刀洞; gwaan1 dou1 dung6)—is nicknamed after its contour, which resembles the mythical weapon wielded by Guan Yu. Besides its impressive fissures and volcanic columns, hikers and scuba divers venture to Basalt Island for its diverse aquatic ecology.

If you are not a big fan of boat trips and kayaking tours, make your way to Cape D’Aguilar instead. Home to the only marine reserve in Hong Kong, Cape D’Aguilar lies on the southern shore of Hong Kong past Shek O. While you might be tempted to dive into the glistening waters, especially when battered by the summer heat, do note that activities including swimming, diving, and fishing are strictly prohibited in the area.

Stroll underneath dramatic cliffs along the coastline and an arch-like formation that resembles a crab. The Crab Cave and its “mouth” are usually marked by a long queue of photographers. You can also climb to the top of the arch for a sweeping coastal view, but be aware of the sharp edges of the cliffs.

Duck’s Eye Cave (鴨眼洞; ngaap3 ngaan5 dung6)—or the Ap Chau Sea Cave—is located on Robinson Island or Ap Chau (鴨洲; ngaap3 zau1), a small island in East New Territories between Kat O and Sha Tau Kok. Ap Chau remained untouched until the late 1920s until fishermen from Tap Mun used the island as an anchorage.

It is the smallest inhabited island in Hong Kong and is composed of red breccia, a type of oxidised sedimentary rock layered with pebbles and calcified fragments. A sea arch—named after its shape, which resembles a duck’s eye—is one of the few sites in Hong Kong where you can observe this landform up close. You can get to Ap Chau by hopping onto a lesser-known ferry route that operates on the weekends and public holidays from Ma Liu Shui.