I love stuff like this.
A lost Mayan city named "Holtun" has been found in the middle of the Guatemalan jungle. Not only has the location been found, but hundreds of largely in-tact buildings remain there as well.
From the NatGeo article:
Using GPS and electronic distance-measurement technology last year, the researchers plotted the locations and elevations of a seven-story-tall pyramid, an astronomical observatory, a ritual ball court, several stone residences, and other structures.
Source -> http://news.nationalgeographic.com/news/2011/04/110426-maya-lost-city-holtun-science-guatemala-ancient/