Avebury, the Neolithic monument just north of Stonehenge, may be best known for its outer stone circle, the largest of its kind in Europe, which encompasses the entire site. Archaeologists have now discovered that within one of its inner circles, there was an earlier, square formation. Using radar technology, they have identified evidence of an arrangement of stones that they believe commemorated the footprint of a Neolithic house, a structure built as early as 3500 B.C. While past theories have postulated that Avebury was constructed from the outside in, these findings suggest the site instead sprang from a single building. “One interpretation is to see it like ripples on a pond,” says Mark Gillings of the University of Leicester. “The house decays, its position is marked with a huge standing stone, and its orientation and shape are marked by the square. It may have been 300 years after the house was built that they decided to memorialize it,” he explains. “By that stage it might have even been an ancestral place that had slipped into myth and legend.”

Construction workers on Rome’s new “C” metro line uncovered what is believed to have been part of the Aqua Appia, Rome’s oldest-known aqueduct, which dates back to 312 B.C. The remains were found near the Colosseum, at around 55 to 60 feet below Piazza Celimontana, a depth usually unreachable by archaeological excavation, says Simona Morretta of the Archaeological Superintendency of Rome. The section of aqueduct measures 6.5 feet tall and is made up of large gray, granular tufa blocks arranged in five rows. “The total absence of any traces of limestone inside the duct suggests that its use over time has been limited,” says Morretta, “or that the structure was abandoned just after a maintenance intervention.” It stretches for more than 100 feet and continues beyond the investigation area bounded by concrete bulkheads.

Excavations at Jebel Irhoud, near Morocco’s west coast, have uncovered the 300,000-year-old bones of some of the earliest members of the Homo sapiens lineage. Human bones were first discovered at the site in 1961, and their strange combination of archaic and modern features intrigued scientists, who guessed they belonged to Neanderthals and dated to about 40,000 years ago. In 2006, a team led by Jean-Jacques Hublin of the Max Planck Institute for Evolutionary Anthropology reopened excavations at Jebel Irhoud. This year, they revealed their results, providing a glimpse of the earliest members of the ancestral line that led to modern humans.

The Jebel Irhoud hominins apparently lived 350,000 years after Neanderthals and Homo sapiens last shared a common ancestor, long enough for the two lineages to develop some obvious differences. The people of Jebel Irhoud had flat and short faces like modern humans, but their brains were more elongated and their teeth much larger. Their brow ridges were also more prominent than those of humans living today, but not as heavy as those of Neanderthals.