Ancient stone "potbelly" sculptures on display in a park in Guatemala are magnetized on certain spots, suggesting the pre-Columbian civilization that made them had a practical knowledge of magnetism . Eleven of these sculptures of giant heads and distorted bodies, known as "potbellies" because of their distinctive rotund shapes, are on display in a plaza in the small town of La Democracia, near Guatemala's Pacific coast. They were installed there in the 1970s after being brought from ancient sites in the nearby Monte Alto region. Guatemalans are thought to have created these potbelly sculptures more than 2,000 years ago, which would date them to the Late Preclassic period of Mesoamerican civilizations. Previous studies of the sculptures had suggested several had magnetic anomalies on their surfaces.