A roundabout in Democratic Republic of Congo's capital Kinshasa has become the latest site occupied by a mystery monolith after similar objects in the United States and elsewhere caught the fancy of science-fiction fans. On Wednesday morning, a crowd of curious onlookers in the Bandal neighbourhood snapped selfies and debated the possible origins of the 12-foot metallic structure that appeared over the weekend, before being pushed back by armed police. Similar alien-looking pillars were spotted in a Utah desert in the United States in November, and then in Romania and Turkey, drawing comparisons to the monoliths in Stanley Kubrick's 1968…