Dacca: Military parade for 10th year of Independance, train ride to Sylhet, Cox's Bazar: 150km beach (longest in the world), Armenian Church, Star Mosque, Lalbagh Fort, Liberation War Museum, Museum of Independence, Bangladesh Air Force Museum, Dacca Zoo, Sadarghat boat trip in Dacca.
Rajshahi Varendra museum, Ancient temples in Mahasthangarh, Jaggadala. Sunderbans National Park to visit by boat from Mongla, calculate a whole day, it is a shared UNESCO with India, Bagerhat UNESCO mosques, also the Nine dome mosque, and Shait Gumbad mosque. Panam City as a wonderful ghost town, maybe as a convenient stop on the way to Chittagong.