|Antikythera mechanism fragment, image credit: Wikimedia Commons CC BY 2.5|
Are any of the artifacts pre-Flood? Probably not, since the Genesis Flood was a violent, catastrophic event. I won't say it's impossible that some remarkable antediluvian objects have been found, but I will rule out the ancient cities. For more details, click on "Ancient civilizations and modern man — Were ancient cultures more advanced than many evolutionists believe?" You may also want to see "Why the electric battery was forgotten".