Dhaka's planetarium, housed in a distinctive domed building on Bijoy Sarani Avenue near the Farmgate intersection. Shows run throughout the day covering astronomy and space science; the Bangla-language shows are aimed primarily at school groups, but English sessions are sometimes available. The building itself is a concrete dome of 1960s institutional architecture — less interesting from outside than a planetarium has any right to be, but the interior projections are good.
A reasonable option for a couple of hours if you have children or an interest in astronomy. More importantly, the surrounding area gives a sense of the mid-city Tejgaon neighbourhood, distinct in character from both old Dhaka and the modern business districts.