ricebird. Feral pigs were introduced to the valley by the first Polynesian settlers. While this is an ideal environment for the pigs, these animals are a serious threat to the rest of the valley. Flora The expanse of land in Kahana Valley from the sea to the mountains contains many different vegetation zones. The lowlands consist of koa (Acacia koa), hibiscus, hala (Pandanus tectorius), and pasture. Further up the valley, in the wetter areas, the dominant vegetation consists of mountain apple (Syzygium malaccense), strawberry guava (Psidium littorale), ti (Cordyline fruticosa) and bamboo. Activities Hiking There are two hiking trails in the valley, both of which do not require permits and are suitable for whole families. The first is Kapa'ele'ele Ko'a and Keaniani Lookout Trail. It is a mile long loop that takes a decent hiker roughly an hour. The second is the Nakoa Trail, which is named so for the numerous koa (Acacia koa) found along this 2.5-mile trail through tropical rainforest. Hikers on this trail can swim in the Kahana stream, which is traversed twice. Camping and hunting There are ten campsites located on the beach which can be used by permit only. Hunting is also permitted within designated boundaries on weekends and holidays only, and by permit only. See also List of Hawaiian state parks References State parks of Hawaii Protected areas of Oahu Beaches of Oahu