The best known archaeological sites in North America to the public are probably the temples of the classic Maya civilization (~AD 250-900). Uxmal, Bonampak, Tulum, Copán, Tikal—these sites in Mexico, Honduras and Guatemala are great attractions for people drawn to marvel at big prehistoric stone temples.

Nunnery Quadrangle Plaza at Uxmal. Photo by Esparta Palma

An interesting but largely overlooked component of these temples are the plazas—large open spaces around which some of the largest temples are organized. These open spaces were of importance to to the Maya themselves, who used them as places for festivals and ceremonies. This element was documented in an interesting set of articles and a recent book by Takeshi Inomata.

To help you enjoy this interesting aspect of the Maya civilization, I've put together a photo essay of the plazas of a few of the important Plazas of the Maya.

• Spectacles and Spectators: Maya Plazas
• The Role of the Plaza in Maya Festivals, more detail on Inomata's work
• Guide to the Maya Civilization

This January, PBS presents The Human Spark, a three-part documentary series examining what makes us human, what makes us different from every other animal on the planet. The first video, "Becoming Us", covers the amazing range of archaeological and paleontological research over the past decade that has led science to reconsider the roots of our humanity.

Alan Alda (right) with Svante Paabo, whose group at the Max Planck Institute for Evolutionary Anthropology in Germany has sequenced the Neanderthal genome. Photo ©Larry Engel 2008 for The Human Spark

Faithful reader Bob W writes: "I'm a little curious about what archaeology has to say about global warming. I read that the reason that Beringia is no longer above sea level had to do with global warming. Now the scientists are telling us that the sea level will rise with global warming. It rose then, and now you're saying it will rise again? How is that possible? Which of these statements is true?"

Ilulissat Iceberg, Greenland. Photo by kaet44

Both are true, Bob, and oddly enough, for the same reason. The sea level rose at the end of the Pleistocene because glaciers covering all of Canada and parts of North America (not to mention Europe and Asia) melted, a direct result of the global increase in temperature. All that water had to go somewhere: our atmosphere can only absorb so much water. Scientists believe that as the icecaps shrink and the glaciers in Greenland and elsewhere melt, the sea levels will rise again.

• Bering Strait
• Last Glacial Maximum

Looking for a fun way to kill the hours between Christmas and New Year's? Blogger Talking Pyramids has compiled a great list of Egypt-oriented online games.

Talking Pyramids: Ancient Egyptian Games: Online