The availability of high-resolution satellite imagery of Saudi Arabia on publicly available platforms such as Google Earth and Bing Maps has been transformational for archaeology. Within just a few years tens of thousands of sites previously unrecorded and scarcely known to the academic world have been mapped. Especially rich in sites are the successive lava fields (harret) stretching from southern Syria through Jordan and down the west coast of the Arabian Peninsula to Yemen, and characterised by the stone-built structures known to the Bedouin as the ‘works of the old men’. Sites now being revealed include many types familiar from previous research in the wider region but also others of a form previously unknown. ‘Gates’ are one such type, found in large numbers in and around the Harret Khaybar in west-central Saudi Arabia. They are stone-built, the walls roughly made and low as with other ‘works’, but quite unlike them in form. Identification, mapping, and preliminary interpretation imply an early date in the sequence of the works—perhaps the very earliest—but no obvious explanation of their purpose can be discerned. Fieldwork is a desideratum.