Laldighi ("Red Tank") is a square reservoir dating to the Mughal era at the heart of Chittagong's old commercial quarter. The four sides of the tank are lined with steps where locals come to bathe, fish or sit in the evenings, and the surrounding bazaars of Anderkilla and Riazuddin Bazar form one of the busiest markets in the city.
The tank is named for the red lotuses that traditionally grow in it, and a single old kadam tree on the north bank is said to be among the oldest in the city. A useful landmark for finding your way around the old centre — most streets in this part of Chittagong run towards or away from the dighi.