It is cool that autumn is here. It is good to go rural area for a walk. However, a simple country side may be too "natural", let go to a outlying island for fun.
Cheung Chau, is one of the quite popular outlying island in Hong Kong. The town centre is so crowd in weekends since many local people will come to have a walk. Moreover, to have seafood dinner, or BBQ. You can also come to have a walk, no matter have good seafood, you can also rent a room for a night, there is a good seaside hotel located there.
You can see the traditional culture of the people original living in Cheung Chau, most of them are fishermen before, so, you can also enjoy the scenic of the boats in Cheung Chau.
It is very cool to ride in Cheung Chau, you can rent a bike and shuttle around the island. But if you want to hike, you can also go to the hilltop, there is a famous Cave, called Cheung Po Tsai Cave, which is a place a pirate lover called Cheung Po Tsai's to store his treasure before.
Transport: Ferries from Central Pier 5. The Central Pier can be reached by MTR, Exit F, Hong Kong Station.