Thailand's outdoor landscape moves between registers at a pace that rewards planning. The northern highlands around Chiang Mai carry Doi Inthanon National Park — the highest peak in Thailand (2,565 metres), cloud forest, and the twin royal pagodas at the summit above a wildflower meadow — and the Pai Canyon and Chiang Dao Wilderness Area below for cave and limestone hill walking. The Khao Yai National Park near Bangkok is a UNESCO World Heritage site where gaur, Asian elephant, and leopard are all present in a UNESCO-listed forest, and gibbons call at dawn from the canopy above the overnight lodge. The Similan Islands in the Andaman Sea carry the best liveaboard diving in mainland Southeast Asia, with manta ray, whale shark, and leopard shark at sites inaccessible from shore. The Three Pagodas trail near the Myanmar border delivers a different, lower-humidity walking register. The best part is often the hidden gems you were not even looking for. Take it all in.