August 6 is the memorial day when an A-bomb was dropped on Japan's Hiroshima. A ceremony is held every year in Hiroshima Peace Memorial Park on this day, and a lot of cranes of the origami "Orizuru" are displayed there.
Orizuru - paper crane of origami - is one of the general works of the origami, but It is often used as an item of the recovery from a disease and an injuries, the revival from disasters and the pray for peace. For example, there is a case that classmates make and give Senbazuru(千羽鶴: 1,000 paper crane of origami) for the friend who suffered from a serious disease.
Therefore Ingress players of Hiroshima flashed for an interesting idea. Ingress is mobile geolocation game of Google and players are divided into two camp and scramble for portals on a real map. When players tie neighboring portals in lines, they become the aspect. Players of Hiroshima paid attention to this. Because they connected portals well around the Hiroshima Peace Memorial Park, they became the shape of huge orizuru.
This has two important points. Ingress is usable as not only the game but also an art tool. And It's the wonderful art that two camp fighting against each other cooperate and made. It is right good for peace.
You can watch their Orizuru facture here (Japanese).