Mexican archaeologists have found what may be the most significant Aztec ruin in decades, with the unearthing of an altar and a monolith in the busy heart of Mexico City. The 15th century altar, part of the Aztec empire's main temple, was uncovered last weekend near the city's main Zocalo square, along with the 11-foot (3.5-m) stone slab, most of which is still buried under earth and which they think might be part of an entrance to an underground chamber.

News report here: Mexican archaeologists find important Aztec ruins
Be sure to click on the slideshow to the left of the text for pictures of the site.