A wadi is a valley or ravine, bounded by relatively steep banks, which in the rainy season becomes a watercourse; and you will find hundreds of these in Saudi Arabia. In the middle of Riyadh there is a man made oasis called Wadi Namar which was officially opened as a park in April 2012. This natural valley was made through a lot of hard work into a a cool location which follows a paved road up the wadi to the Wadi Namar Dam. This is where everyone can hang out and relax by the water while enjoying the overhead cover provided along with the public restrooms. As you drive up through the wadi enjoy the scenery to include the flowing water located adjacent to the roadway. And once you get there the lake behind the damn is an awesome sight to see.
Bring your own writing instrument and don't let the traffic zipping overhead distract you from your goal.