In Japan's Aomori Prefecture, there is what appears to be a fully preserved, ancient settlement that looks like it was built yesterday, and in some respects, it was.
Dating back to the Jomon period, that lasted somewhere from 11,000 - 300 BCE, the Sannai-Maruyama ruins represent one of the largest examples of life in the area during its height. The ruins were discovered in 1992 while planners were looking into locations for a new baseball stadium, instead finding the remains of a large ancient settlement. As excavations began on the grounds, a number of burial pits were discovered, along with evidence of a number of above ground long houses.
After the excavations discovered what the buildings would have looked like, recreations of the buildings were built atop the ancient remains, using mud, thatch, and wood. Instead of using the information for simple research and accounting, researchers essentially brought the settlement back to life. Tall long houses and wooden towers now stand next to earthen dugouts, all of which look like they are brand new.
Japan declared the site a national historic landmark in 2000, and now the public is allowed to visit the brand new bit of ancient history. There is an indoor exhibition site that also displays a number of the smaller artifacts found in the excavations, should visitors wish to see some of the things that were actually in use millennia ago.