Craters of the Moon:

http://www.nps.gov/crmo/home.htm

Fort McHenry:

http://www.bcpl.net/~etowner/history.html

Statue of Liberty:

http://www.nps.gov/stli/prod02.htm#Statue%20of

George Washington Birthplace:

http://www.nps.gov/gewa/homepg.htm;

http://www.nps.gov/gewa/;

http://www.milebymile.com/main/UnitedStates/Virginia/national_parks/George_Washington_Birthplace.html

Jewel Cave:

http://gorp.away.com/gorp/resource/us_nm/sd_jewel.htm

http://www.nps.gov/jeca/historic.htm

Fort Sumter:

http://www.lbdb.com/TMDisplayBattle.cfm?BID=18&WID=2

http://www.u-s-history.com/pages/h98.html