Afghanistan is landlocked so does not have any beaches, but it does have lakes.
Social nudity is not permitted here, and women wear traditional full-length tunics or burqa/chador.
Also, be aware of the high threat of kidnapping throughout the country. If you are planning to visit Afghanistan and wish to relax in the nude your best bet would be to visit one of the hot springs where social nudity is permitted. We have one listing for Bebi Fatima Hot Springs, but ideally, another country altogether would be best considered.