"The largest tunnel is over 2,000 feet long. Some are large enough for cars to drive through – but they weren’t man-made. Giant ground sloths dug them in #Brazil over 10,000 years ago.

The walls of the tunnels are covered in giant claw marks from the floor to the ceiling. Geologists call the tunnels “paleo burrows,” which are believed to have been dug by a now-extinct species of giant ground sloth as big as #Elephants."