Have you ever stored something in the cloud and wondered where that data goes?  You might be surprised to learn it's in a quiet residential community about 30 miles outside the capital city of Washington, where people jog or walk their dogs around human-made lakes, children's teams practice on soccer fields, and teens play pick-up basketball on community courts.  The majority of the world's internet traffic passes through the town of Ashburn in Loudoun County, Virginia, home to one of the world's major internet exchanges.  "It's amazing when you think about the amount of fiber that's in the ground," says Buddy Rizer, executive director of economic development for Loudoun County. "Both sides of the road pretty much have fiber troughs in them. And now we're putting some fiber in the middle of the roads as well. We want to continue to build on that fiber network."Seventy percent of the world's internet traffic passes through all of that fiber. That's why Ashburn is known as Data Center Alley. The Silicon Valley of the east. The cloud capital of the world. Pretty much any email sent or received anywhere around the globe passes through this town. If you've got something stored in the cloud, it's probably in one of the 100-plus data centers located in Loudoun County."A lot of people, they think about the cloud and their eyes go up. Well, it's not really up," Rizer says. "The cloud is based somewhere and, by and large, the cloud has been based here in Loudoun County, Virginia, in the data centers, the 18-million-square-feet of data centers that we have on the ground here."It all started when America Online moved to Ashburn back in the 1990s. AOL brought fiber and power infrastructure with it. MAE-East, one of the world's first internet exchanges, moved to Loudoun in the late '90s after first forming in 1992."It was a couple guys who got together over some beers and decided that they were going to allow one another to pass traffic back and forth across the different networks that they'd been creating," says John Day, vice president of sales and leasing for Sabey Data Centers.    Other companies followed, each new addition contributing to the creation of the most dense fiber network anywhere in the world. Tech titans like Amazon and Google now have a presence in Loudoun. Northern Virginia's appeal includes reasonably priced land, low-cost-but-dependable electricity, access ...