So ... of course, I've looked it up.
According to Wikipedia, there are many "7 Wonders of the World" type lists including Ancient Wonders, Medieval Wonders, Underwater Wonders, Man-Made and Natural Wonders etc. I guess what happened was that on July 7, 2007 (i.e. 07-07-07) this announcement was made:
New 7 Wonders of the World
Looks like a definitive list as globally voted upon to decide what wonders should stand as a testament to "global heritage throughout history".
There were 21 finalists, but the 7 wonders that made the cut are:
- The Great Wall of China
- Petra, Jordan
- Christ Redeemer, Brazil
- Machu Picchu, Peru
- Chichen Itza, Mexico
- The Roman Colosseum, Italy
- The Taj Mahal, India