
Dhaka is friendly and relatively clean (compared to Indian cities with 5 million people). But there are not many sights to attract visitors.
The most important sights are the Lalbagh Fort, the National Assembly Building, the Baitul Mukkaram Mosque and the national gardens.
When you are staying abit longer, the many markets in town are absolutely worth a visit as well. Once you have spent a second day in Dhaka there is nothing to keep you here, but the possibility of taking a daytrip.