More and more maps of Yemen and the Arabian Peninsula are appearing in digital resources on the Internet. One of these is the David Rumsey Map Collection, housed at Stanford University. This overall collection with downloadable images in high resolution contains over 150,000 images, including some on Yemen, as well as other parts of the Middle East. The search function is easy to use. The maps are available under the Creative Commons License but not for commercial use.
Below are two closeups of maps that include Yemen.