Soyo offers little in the way of conventional tourism, but the landscape around it is genuinely striking. The Congo River estuary — one of the widest river mouths in Africa — has a wild, remote beauty, with wide sandbars, large numbers of birds, and the contrast between freshwater and ocean. The area around the estuary and the coastline north of town is worth exploring if you have transport.
The town itself is primarily an oil industry hub, and most of what you see reflects that — industrial infrastructure, company facilities, and the support services that go with them.