Circular Road is near Singapore River which is one of the oldest areas in Singapore. The place has undergone significant redevelopment. There's quite a variety of shophouse designs around here. If you look above the roofs of the shophouses that line the streets, you'll see many commercial tall buildings, mostly owned by banks, around the area.
It's relatively deserted in the morning during weekends but during evening time when the pubs are open, it will be crowded with drinkers and party goers. And if you head over to the next street by the riverside, there are restaurants serving seafood --- be careful not to get ripped off so always ask for the price in advance.