Some Google Earth enthusiasts have found a strange and unexplainable grid pattern in the middle of China's Gobi Desert.
Res Obscura is a blog by Ben Breen, a graduate student of early modern history, which styles itself "a compendium of obscure things." Indeed, even the asides are full of wonder, such as the one about Boy, the famous Royalist war poodle of the English Civil War, which is but a short addendum to a post about witches' familiars. Here are some of my favorite posts, Pirate Surgeon in Panama (and a related post about 18th Century Jamaica), vanished civilizations, asemic pseudo-Arabic and -Hebrew writing in Renaissance art, and a series of posts about the way the Chinese and Japanese understood the world outside Asia in the early modern period (Europeans as 'Other', Europeans as 'Other,' Redux and Early Chinese World Maps).
The Agnostic Cartographer : How Google’s open-ended maps are embroiling the company in some of the world’s touchiest geopolitical disputes.
Antique Maps of China A database of 230 maps, charts, pictures, books and atlases from the Special Collections of The Hong Kong University of Science and Technology Library. You can browse thumbnails of maps dating back to the 15th century, then download a splendid colour PDF, for example, the 1923 map Carte des environs de Peking. There are also some world maps and ones of a few other places.