The 5th Norfolk Battallion
https://www.thevintagenews.com/2017/08/01/the-5th-norfolk-battalion-vanished-without-a-trace-during-the-gallipoli-campaign-in-world-war-i/
http://mysteriousuniverse.org/2015/03/the-mysterious-vanishing-battalion-of-wwi/

The Lake Michigan Three
http://www.nydailynews.com/news/justice-story/3-girls-beach-found-article-1.1216303
http://www.nwitimes.com/news/local/bruhl-blough-miller-dunes-disappearance-remains-unsolved-years-later/article_3df371d6-0ba6-5611-bfa6-9af13f00f34c.html

Flight 19
https://en.wikipedia.org/wiki/Flight_19
https://www.history.com/news/the-mysterious

The 9th Legion
https://en.wikipedia.org/wiki/Legio_IX_Hispana
http://www.bbc.co.uk/news/magazine-12752497

The Flannan Isles Lighthouse
https://en.wikipedia.org/wiki/Flannan_Isles_Lighthouse
http://www.historic-uk.com/HistoryUK/HistoryofScotland/The-Eilean-Mor-Lighthouse-Mystery/

The Mary Celeste
https://en.wikipedia.org/wiki/Mary_Celeste
https://www.smithsonianmag.com/history/abandoned-ship-the-mary-celeste-174488104/

Lake Anjikuni Settlement
https://en.wikipedia.org/wiki/Angikuni_Lake
http://mysteriousuniverse.org/2011/07/village-of-the-dead-the-anjikuni-mystery/

Kuldhara
https://en.wikipedia.org/wiki/Kuldhara
https://www.thebetterindia.com/48562/abandoned-cursed-200-year-old-village-kuldhara-rajasthan/

Hoer Verde
http://www.unexplainable.net/info-theories/the-village-that-vanished.php
http://www.realclear.com/history/2016/02/16/the_bizarre_sometimes_real_stories_of_towns_that_totally_disappeared_12867.html

Roanoke Colony
https://en.wikipedia.org/wiki/Roanoke_Colony
https://www.history.com/news/ask-history/what-happened-to-the-lost-colony-of-roanoke