The Bara Katra and Choto Katra are the remains of Old Dhaka's great Mughal caravansaries, built in 1643 and 1663 for merchants and travellers moving through the city. Only fragments survive, but the scale of the gateways and brickwork still hints at how grand these trading inns once were.
They are not polished monuments. The surviving structures sit in the dense fabric of old streets, worn down and partly swallowed by later buildings. That roughness is part of the experience, but go with realistic expectations and combine them with nearby Lalbagh Fort, Ahsan Manzil, and the riverfront.