A popular day trip from Kinshasa despite the expensive 4WD hire (US$200) necessary to get here, the gorgeous 65m-high Zongo Falls are one of DRC's most spectacular sights. Getting to the viewpoints involves some hiking (bring shoes that you don't mind getting muddy), but watching the water roaring over the precipice into the river below is unforgettable. There's the Seli Safari Resort here, where it's possible to have lunch or overnight.
The falls are 130km from Kinshasa, so expect a four-hour journey each way.