One of the most extraordinary examples of ancient engineering is the Sacred Well of Santa Cristina in Sardinia, Italy.
Built over 3,000 years ago, this remarkable structure is aligned with both solar and lunar cycles.
During equinoxes, sunlight illuminates the well’s depths, and every 18.6 years, moonlight shines directly into its chamber during a major lunar standstill.
These alignments reveal the Nuragic civilization’s advanced understanding of astronomy, making this 3,000-year-old well a stunning achievement that continues to fascinate researchers today.