The main tourist attractions within Te Wahipounamu are Milford Sound and Milford Track, Lake Te Anau and Kepler Track, the Routeburn Track and Mount Aspiring, Aoraki / Mount Cook and the Tasman Glacier, and Franz Josef Glacier and Fox Glacier. There are only two main roads in the region, the Haast Highway and Milford Highway. Along these highways, which are referred to as the Heritage Highway corridors, is a network of ten visitor centers and a multitude of nature walks. A main attraction to Te Wahipounamu, and New Zealand in general, is the natural landscape. A study found that key motivating factors for visitors to Te Wahipounamu are the scenery and recreational activities. Tourism within Te Wahipounamu is nature-based, ‘green' tourism. There is a combination of nature and adventure tourism. There are some strictly nature based tourism activities such as walking in the Natural Parks, whale-watching, and boat tours in the Fiordland Sounds. Then there are activities such as tramping or trekking, which contain adventure components like crossing rivers or mountain passes while enjoying the natural scenery. Even the adventure activities like glacier walks, rafting, and climbing take place in the natural environment.