The World Grid Theory

The World Grid Theory has become a popular belief for many.  It states that Earth is surrounded by a planetary grid which is comprised of geometric patterns that have intersecting points that some say are vortexes. These points or vortexes are believed by ancient astronaut theorists to be portals or doorways to other dimensions. Over the years, scientists and researchers have discovered that ancient megalithic sites and places with strange magnetic anomalies can be found at these intersecting points.

Earth Grid- photo by hohodigidea @ deviant art

"While this allegation may seem fantastic at the outset, the idea of the earth as a geometric shape goes back in history at least to the Pythagorean school of thinking in ancient Greece. Its famous adherent, Plato, wrote that "the earth, viewed from above, resembles a ball sewn from twelve pieces of skin." The other part of the grid, says the three Russians, causes the ball to be sewn from twenty equilateral triangles, making of the planet an icosahedron. By superimposing the entire dual grid over the face of the planet, the researchers say they have discovered what possibly may be the earth's energy structure or skeleton." (Chris Bird)

Here is a list of commonly known ancient megalithic sites and places where strange magnetic anomalies occur and those that consist of other important features- interestingly they can be found at the points of intersection.
1) The Great Pyramid
2) Easter Island
3) The Bermuda Triangle
4) The Nazca Lines
5) Bimini Road
6) Xian Pyramids
7) Ankor Wat
8) Dragon's Triangle
9) Borneo

This was just a short list that I put together - there are many more fascinating places with high strangeness that have been discovered around the world.

Popular reading material on the subject: 
Anti-Gravity and the World Grid (Lost Science (Adventures Unlimited Press))
The Sacred Network: Megaliths, Cathedrals, Ley Lines, and the Power of Shared Consciousness