Bronze Age stone circles with markers for solstices and equinoxes. Precision measurements show they tracked lunar standstills, implying knowledge of the 18.6-year cycle.
A celestial calculator in the desert
In the Kyzylkum desert of Uzbekistan, a series of unassuming stone circles forms a sophisticated astronomical observatory dating to the 2nd millennium BCE. Known as the Uzunkyr alignments, this site was a calendar. Its builders, associated with the Late Bronze Age Tazabagyab culture, engineered the site to track the annual solstices and equinoxes and the far more complex 18.6-year lunar standstill cycle.
The site consists of multiple circular and rectangular stone settings spread across a low hill. The main structure is a central circle, approximately 100 meters in diameter, with outlying stones positioned at specific astronomical azimuths. These carefully placed markers align with the points on the horizon where the sun rises and sets on the longest and shortest days of the year. This allowed the inhabitants to precisely mark the changing of the seasons, important for agricultural and pastoral communities. The people of the Tazabagyab culture were known to practice small-scale irrigation agriculture, making such a calendar a practical tool for survival.
Tracking the lunar extremes
The most advanced feature of the Uzunkyr site is its ability to track the lunar standstills. The moon does not follow the same path across the sky each night. Over a period of 18.6 years, the northern and southernmost points of its monthly risings and settings oscillate between a maximum (major standstill) and minimum (minor standstill) range. Observing this cycle requires meticulous, long-term observation and a durable method of recording the positions.
At Uzunkyr, specific standing stones are aligned to these extreme lunar positions. An observer at the circle's center would see the moon rise or set over these markers only at the peak of the major or minor standstill. This shows a deep, multi-generational understanding of celestial mechanics. While structures like Stonehenge are also theorized to have lunar alignments, the clarity of the markers at Uzunkyr is an example of Bronze Age archaeoastronomy. The builders, likely early Indo-Iranians, had astronomical and mathematical knowledge that allowed them to create this permanent and precise celestial calculator in the middle of the vast Eurasian steppe.
💡Fun Facts
The 18.6-year lunar standstill cycle is caused by the 5.1-degree tilt of the Moon's orbit relative to Earth's orbit around the Sun.
The people who built Uzunkyr belonged to the Tazabagyab culture, which flourished around 1850 to 1500 BCE in the lower Zeravshan valley.
The name "Uzunkyr" translates from Turkic languages as "long hill," a simple description of the landscape where the observatory is found.
The Tazabagyab people were skilled metallurgists who likely controlled the regional trade in copper, tin, and turquoise.
The site is an open, unprotected archaeological area and is accessible at any time.
Admission
Free.
Accessibility
Located in a remote desert region, the site is not serviced by paved roads. Access requires a 4x4 vehicle and preferably a local guide. The terrain is natural, uneven, and exposed to the elements.