Chewing the mixture of areca nut and betel leaf is a tradition, custom, or ritual which dates back thousands of years in much of the geographical areas from South Asia eastward to the Pacific. It constitutes an important and popular cultural activity in many Asian and Oceanic countries, including Pakistan, the Maldives, India, Nepal, Sri Lanka, Bhutan, Bangladesh, Burma (Myanmar), China, Laos, Thailand, Brunei, Malaysia, Indonesia, Cambodia, Vietnam, Taiwan, the Philippines, Palau, Yap, Guam, Papua New Guinea, the Solomon Islands, and Vanuatu. How or when the areca nut and the betel leaf were first combined into one psychoactive drug is not known. Archaeological evidence from Thailand, Indonesia, and the Philippines suggests they have been used in tandem for at least 4000 years.