History

1.Mughal Edifices in ruins under Britsh rule 1757-1947
2.Partion of Bangla 1905 its annulment in1911 
3.Mughal Bridges of Dhaka

4. Liberation of 1971
5.Sonargong 

Ref:
http://www.wikipedia.com
http://www.banglapedia.org
http://bengalpartition.tripod.com
http://www.britannica.com
http://www.apnaorg.com

Bangladesh in pictures by Thomas Streissguth (available in google)