The Great Pyramid in Egypt is perhaps the most iconic human structure in the world and thanks to the efforts of the Egyptian Autistic Society, it will Light It Up Blue on April 2, 2015 in honor of World Autism Awareness Day.

The Great Pyramid of Giza is believed to have been built in just 20 years around 2560 B.C. as a tomb for Pharaoh Khufu. It originally stood at 451 feet tall and was the tallest man-made structure in the world for 3,800 years. It is the oldest and most intact of the Seven Wonders of the Ancient World.

The pyramid consists of an estimated 2.3 Million blocks weighing an estimated 5.9 Million tonnes.  

Source of information: https://www.autismspeaks.org/