Yemen has some of the most fertile lands in the entire Middle East, and yet, for the most part, they're not developed to their full potential.
Along its Red Sea coast there's a flat sandy plain that extends the length of the country. The Gulf of Aden coastline is covered by a narrow, rocky, and relatively flat plain, fronted by hills that rise into the rugged mountains, central and west.
To the north of those central mountains, the high desert slopes down through fertile plains into the interior of southern Saudi Arabia, and the endless sands of the Rub' Al Khali Desert - the famous "Empty Quarter."
Yemen's highest point is Jabal an Nabi Shu'ayb at 12,336 ft. (3,760 m).
There are no perennial lakes and rivers, however, in the northern highlands some river valleys (wadis) small streams exist (fall and winter) but fade away quickly in the summer heat.