Beautiful mountains behind Manokwari are a nature reserve famous for their high biodiversity, notably birdwing butterflies. They are also a popular birdwatching area with several endemic species. The Arfaks also offer excellent trekking possibilities through steep, forested hills. There are lots of traditional villages of thousand-legged houses" here, though the people themselves wear modern dress. That said, they are very friendly and trekking here is far less commercialised than in the central highlands.