Parque Arqueológico do Solstício

>>On the winter solstice of December 21, the shortest day of the year in the northern hemisphere,[clarification needed] the shadow of one of the blocks disappears when the sun is directly above it.

This is not quite right. On that day the Sun is directly above São Paulo.

At the archaeological site: Latitude = +2.62°, Solar declination ≈ −23.44°, Difference = about 26.06°.

Therefore, at solar noon: Sun altitude ≈ 90° − 26.06° = 63.94°. Consequently, at that particular latitude, a normal vertical stone cannot have its shadow disappear because the Sun is directly overhead on December 21.

Stonehenge is always mentioned as reference but you have much much older ones:

Göbekli Tepe (Turkey) ~9600 BCE Almendres Cromlech (Portugal) ~5900 BCE

My comment few days ago [1] now look strangely prophetic. We only need to find 3 more Stonehenges.

[1] https://news.ycombinator.com/item?id=49507810#49510204

I love these random appearances of Wikipedia pages on the HN front page.

I'm Brazilian, and this is the first time I've heard of this park.

[stub for offtopicness]

[...submitted title "Amazon Stonehenge: Parque Arqueológico do Solstício" kind of asked for it...]

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