Yemen is a difficult country to get around, but the rewards for the perseverent tourist are an unforgettable experience, populated with very friendly and open hosts. Despite being adjacent to Saudi Arabia and on the same peninsula as the United Arab Emirates, Yemen is definitely a place apart. Yemen has a narrow coastal plain backed by flat-topped hills and rugged mountains; dissected upland desert plains in center slope into the desert interior of the Arabian Peninsula. For trips outside the capital, and most within it, a car (preferably 4WD) is necessary as roads are frequently unpaved and very steep. Maps are also not as reliable as they are in other countries, so engaging the services of a local driver may be a useful expense. Additionally, most travel outside the capital will require a travel permit (tasriih), which must be applied for a number of days in advance and will be examined at checkpoints along the way. This may seem inconvenient, however it is designed to prevent travelers unwittingly venturing into areas of tribal unrest - and vice versa. Some areas of the country are off-limits to travel without military escorts, and still other areas are totally off-limits to travel. While the concept of staying informed about local conditions in your intended destinations is an overused one, in Yemen it is essential, as failure to do so may result in kidnappings or worse. The usual Middle Eastern shared taxi system exists in Yemen.