Nine months after President Donald Trump took office, the first tangible signs of progress on one of the central promises of his campaign have appeared along the U.S. border with Mexico.
A couple of miles (km) from the bustling Otay Mesa border crossing in San Diego, eight towering chunks of concrete and steel stand as high as 9 meters (30 feet) tall against the sky, possible models for what Trump has promised will one day be a solid wall extending the full length of the southern border, from California to Texas.
Whether any of the eight different prototypes, constructed over the last month, become part of an actual wall remains highly uncertain.