Earth's Unsolved X-Files

Poveglia
http://www.mentalfloss.com/blogs/archives/55234

Overtoun Bridge
http://www.dailymail.co.uk/news/article-411038/Why-dogs-leapt-deaths-Overtoun-Bridge.html

Holes in Russia
http://englishrussia.com/2007/05/24/holes-in-the-ground/

The Solway Firth Spaceman
http://www.cumberlandspaceman.co.uk/spaceman-home/the-real-cumberland-spaceman/

Moving Coffins of Barbados
http://www.profilingtheunexplained.com/mysterious_happenings/moving_coffins_of_barbados.html

Dyatlov Pass
http://aquiziam.com/dyatlov_pass_1.html

The Bloop (and other mysterious ocean sounds)
http://io9.com/5883622/meet-the-bloop-the-mysterious-sound-from-the-bottom-of-the-pacific-ocean

Versailles Time Slip
http://www.kathleenmcgowan.com/site/index.php?option=com_content&view=article&id=52:the-mystery-of-the-versailles-time-slip&catid=38:articles&Itemid=62

The Somerton Man
https://www.eleceng.adelaide.edu.au/personal/dabbott/wiki/index.php/Final_report_2009:_Who_killed_the_Somerton_man%3F

Cokeville Miracle
http://www.kajama.com/index.php?file=articledetail&id=3AE5295E-5BDB-4E79-8832-F08F531343BA&PageNum=1

Voynich Manuscript
http://www.voynich.nu/

Animals in Stone
http://paranormal.about.com/od/earthmysteries/a/aa011704.htm

Weird Rain
http://paranormal.about.com/od/earthmysteries/a/Weird-Weird-Rain.htm

Hessdalen Lights
http://www.ghosttheory.com/2012/08/17/scientific-paper-on-the-hessdalen-lights-phenomenon

The Ourang Medan Mystery
http://mysteriousuniverse.org/2011/11/death-ship-the-ourang-medan-mystery/

Kryptos
https://en.wikipedia.org/wiki/Kryptos