Angkor Vat, one of the most famous temples in the world, was constructed between 1113 and 1150 by King Suryavarman II. Unlike most Khmer temples, which are oriented eastward toward the sunrise, Angkor Vat faces west. This unusual alignment was not chosen randomly—it was part of a larger astronomical design. The temple's central axis is precisely aligned with the sunrise during the spring and autumn equinoxes, when day and night are of equal length. This alignment is confirmed by the temple's intricate bas-reliefs, which include 91 asuras (mythical beings often depicted as demons) to the south and 88 devas (celestial beings) to the north. These numbers correspond to the days between the equinoxes and the solstices, showing a deep understanding of celestial cycles. NASA officially recognizes Angkor Vat as an ancient observatory, noting its alignment with not only the equinoxes and solstices but also specific lunar events. The temple was not merely a place of worship; it was also a tool for measuring time and marking important seasonal changes. The design required precise geometry and long-term observation of the sky. For example, the position of a famous bas-relief depicting the "churning of the ocean of milk" aligns exactly with the spring equinox. The slight misalignment—by two to three degrees—results in the sun rising just one or two days before or after the actual equinox, but this does not diminish the overall accuracy of the structure. The construction of Angkor Vat involved an exceptional mastery of both architecture and astronomy. The layout of the temple and surrounding land was planned to ensure that the rising sun would align perfectly with the top of the central tower during the equinoxes. This required careful observation over many years and an advanced knowledge of celestial mechanics. The builders successfully merged science, architecture, and spirituality into a single, harmonious design. Today, Angkor Vat is not only a stunning example of ancient artistry but also a "stone clock" that continues to mark the passage of time with remarkable precision. Angkor Vat has become a major tourist attraction, with thousands of visitors gathering each year to witness the equinox sunrise. During peak seasons, more than 30,000 people have been recorded at the site, and in recent years, the spring equinox attracted over 85,000 visitors over three days. The Cambodian National Authority for Apsara manages the site and promotes these events as a national cultural highlight. Despite modern technology allowing for the scanning of large areas of the surrounding jungle, many mysteries remain. Researchers and travelers alike wonder how many other astronomical secrets are still hidden beneath the vegetation in the Angkor region. As exploration continues, it is possible that more precise alignments and ancient knowledge may yet be uncovered.