Northeast of Dallas, I know of at least 2 being built, and I suspect at least 3 others. I'm sure there are many, many more.

RagingWire is possibly the largest single company building a single campus/facility at the moment[0], and only about 2 miles from my house. It's quite impressive when you drive by and see the utterly massive power substation they built across the street too.

While the Telecom Corridor[1] name is somewhat dated, it's still growing.

[0]: http://www.ragingwire.com/wholesale/wholesale-data-center-da...

[1]: https://en.wikipedia.org/wiki/Telecom_Corridor

edit: formatting