Time Out says
Tap Mun, which sits off the coast of Sai Kung Country Park, is also known as Grass Island. The island is composed of rolling, grassy hillocks complete with wandering cows. It is also home to a few hundred Hakka and Tanka people. The island has an exciting history as a smuggling and pirate haven, although its now-sleepy streets belie this. Tap Mun is a popular spot for both camping and kite-flying and boasts several rocky beaches.
A trio of temples also lives on the island, located near the main village, which date back to the 18th century. Legend has it there was once a pirate’s tunnel that led from the altar of the Tin Hau temple all the way out to the sea. Also, make sure you take a look at the abandoned King Lam School on the hill above the village. It was built in 1957 and, when it closed in 2003, famously had only one pupil.
Starts at the fisherman’s village by the pier and take a stroll up to the hilltop in the middle of the island. The path offers panoramic views and a refreshing breeze, even on the hottest day. Once you’re all hiked out, head back down to the village’s main restaurant, Sun Yau Kee (新有記) to refuel on their famous sea urchin fried rice.
How to get there: From the Sai Kung Bus Terminus, get the 94 bus to Wong Shek Pier. The ferry runs every one or two hours throughout the week. Ferries also run, less regularly, from Ma Liu Shui Ferry Pier.