A Prehistoric Observatory
The Mnajdra Temple Complex consists of three distinct structures built between 3600 and 2500 BCE. The oldest, the Upper Temple, dates to the Ġgantija phase (3600-3200 BCE). The Middle and Lower Temples were constructed later, during the Tarxien phase (3150-2500 BCE). These buildings are not interconnected; each has its own entrance but they share a common forecourt. The builders used two types of local limestone: hard, durable coralline limestone for the external walls and softer globigerina limestone for the more sheltered interiors and decorative elements.
The Lower Temple is a precise solar observatory. At sunrise on the spring and autumn equinoxes, a beam of light passes through the main doorway and illuminates the central axis of the structure, striking the back wall of the innermost apse some 15.4 meters from the entrance. During the summer solstice, the first rays of sunlight strike the edge of a large megalith to the left of the central passage. On the winter solstice, the light illuminates the corresponding megalith on the right side. This intentional alignment shows an understanding of solar movements, it is one of the world's oldest known solar calendars. No human remains were found in the complex, but the discovery of sacrificial flint knives, animal bones, and possible tethering points suggests its use for religious or ceremonial purposes.