If you have only 3 or 4 hours to spare and don't want to worry about catching buses and finding your way around, Cheung Chau is your best bet. In fact, if I were forced to select only one island to show visiting friends on a limited time schedule, Cheung Chau would be it. Only 12km (7 1/2 miles) from Hong Kong Island, it's a 55-minute ride by ordinary ferry from outlying ferry pier no. 5 in Central, with ferries leaving approximately every hour and offering scenic harbor views from the outdoor deluxe-class deck. Even quicker are the Fast Ferries, also departing every hour or so and making the trip in 30 minutes (but these don't have outdoor decks). Despite its name (Cheung Chau means "Long Island"), Cheung Chau is a tiny, dumbbell-shaped island (only 2.5 sq. km/1 sq. mile), with more than 25,000 residents concentrated in a thriving fishing village. There are no cars on the island, making it a delightful place for walking around and exploring rural village life. The island is especially popular with Chinese families for its rental bicycles, beach (you might want to bring your bathing suit), and basic rooms and apartments for rent, but my favorite thing to do here is to walk the tiny, narrow lanes of Cheung Chau village.
Inhabited for at least 2,500 years by fisher folk and serving as a haven for smugglers and pirates until the 1920s, Cheung Chau still supports a small population of fishing families, with fishing and tourism the island's main industries. The waterfront where the ferry lands, known as the Praya, buzzes with activity as vendors sell fish, lobster, and vegetables. The village itself is a fascinating warren of narrow alleyways, food stalls, and open-fronted shops selling everything from medicinal herbs and incense to dried fish, rice, haircuts, and -- a reflection of the island's tourist trade -- sun hats, sunglasses, and beach toys.