Long Harbour's geography is unusual. The inlet runs roughly north-south, elongated and sheltered, before meeting an interior hill called Tung Sam Kei Shan — Long Hill — at a promontory called Tung Sam Kei Tsui. Here the harbour divides. The East Arm, Chek Keng Hau, bends toward the village of Chek Keng; the West Arm, Ko Tong Hau, points toward Wong Ma Tei and Ngau Wu Tun. The island of Tap Mun guards the harbour mouth, sitting in the broader waters of Mirs Bay and deflecting the open-sea swell that would otherwise make the inner reaches uncomfortable.

From above, the forked shape is distinctive — a liquid Y set into the green hills of the Sai Kung Peninsula. Sharp Peak, at 468 metres the dramatic southeastern summit of Sai Kung, is visible from the Tai Tan Country Trail on the western edge of the harbour's catchment area. The landscape here is among the least developed in all of Hong Kong.

Most of Hong Kong's remote villages were eventually connected to the road network in the twentieth century, losing their isolation to development. The settlements around Long Harbour were not. Tap Mun, Wan Tsai, and Chek Keng have no road access. Ko Lau Wan, Tai Tan, Tan Ka Wan, and Tung Sam Kei are similarly cut off. These are not abandoned places — people live in them, and visitors come to walk the surrounding country park trails — but the absence of roads has kept them in a kind of enforced stillness that feels remarkable against the backdrop of one of the world's most urbanised territories.

The communities that grew here were fishing villages and small-farming settlements, their populations tied to the water and the land rather than the colonial city to the south. Many have shrunk considerably as younger generations moved to the urban areas for work and education. What remains is a small permanent population and a steady flow of hikers and weekend visitors who arrive by boat and leave by the same means.

The kai-to — a small motorised ferry that serves communities without road access — is one of Hong Kong's enduring functional traditions. From Wong Shek Pier, at the head of the West Arm where the road finally reaches the water, kai-to routes branch out to the harbour's various villages. A second hub at Ma Liu Shui, on the MTR East Rail line near Sha Tin, provides another connection point for travellers coming from the urban core.

The boats are small, built for practicality rather than comfort, and the schedules are modest. But for the villages around Long Harbour, the kai-to is not a heritage experience — it is the only way in and out. Fishermen, hikers, villagers returning from town, occasional researchers and birdwatchers: the same small boats serve all of them. In weather that keeps larger vessels in port, the kai-to captains judge conditions by experience built over years on these specific waters.

Long Harbour is an inlet of Mirs Bay, a body of water shared between Hong Kong and mainland China that sits at the eastern edge of the Pearl River Delta. The bay's waters are generally calmer than the open South China Sea approaches, and the Sai Kung Peninsula's rugged coastline creates dozens of inlets, beaches, and headlands that remain largely undeveloped. Long Harbour is one of the larger and more sheltered of these inlets.

The peninsula as a whole was designated a UNESCO Global Geopark in 2009 — a designation recognising the volcanic and sedimentary geology that gives the area its distinctive landscape of hexagonal rock columns, sea stacks, and dramatic headlands. Long Harbour itself sits within this wider protected landscape. The hills above the harbour are country park; the waters below are fished by the same families who have worked them for generations. The combination of landscape protection and genuine remoteness has preserved something here that most of Hong Kong long ago traded for development.