|Paleo Burrows of South America, Brazil|
possibly hundreds of kilometers of weird tunnels, it seems they were dug out by extinct animals
|Aqueduct of Loukou, Greece|
certainly an unusually looking one! was it made of mud bricks that melted and started flowing down or?
|Giant Sinkhole , Guatemala |
|Giant Sinkholes, Russia |
|Tessallated Pavement, Eaglehawk Neck, Tasmania, Australia |
curiously shaped boulders, some suggest they could be very ancient statues
|Giant's Causeway, Ireland|
natural "polygonal masonry"
|Cape Stolbchaty, |
natural columnar basalt formations