Lake Superior Ice Caves on Grand Island, just off the shore in Munising, Michigan. A short walk from Sand Point Beach across frozen Lake Superior will leave you at the base of ice curtains more than 30 feet tall and stretching hundreds of feet wide.
In August of 2007 astronomers located a gigantic hole in the universe. This empty space, stretching nearly a billion light-years across, is devoid of any matter. A radical and controversial theory proposes that it is a "Universe-in-mass Black hole"