A helping of pretty: Crop circles
... No, I don't believe aliens are responsible for crop circles. Their creators are fiendishly clever, I grant you, but they're definitely human. (Also, why are humans so desperate to attribute such intelligence to extra-terrestrials? Our species discovered electricity, penicillin, dynamite: it's hardly a great leap of faith to assume we can also tump down barley fields at night to create artistic masterpieces.)
The latest crop circle, Jellyfish, is 600 feet long and extremely beautiful.
Even more impressive, however, was the 2008 crop circle in Wiltshire. 150 feet wide and set out in a seemingly random pattern, a retired astrophysicist worked out its true meaning here. Please, go read. You'll be VERY impressed.