From the BBC News YouTube Channel:

“A pre-colonial astrological observatory in the Brazilian rainforest was built to be aligned to the sunrise on the December solstice – which fell on 22 December in 2015. The so-called Amazonian Stonehenge, in Brazil’s northern-most state Amapa, is believed to have been constructed over 1,000 years ago. But the site was only discovered in 2006, and plans are now are afoot to make it a national archaeological heritage park.”

A look at a henge in Brazil and how its discovery led to the unintentional destruction of its surrounding environment. “I destroyed thirty percent of the site, innocently… not knowing what it was.” Also mentions a potential UFO encounter and strange sounds coming from the ground.