The 2.1 km cable-stayed bridge over Sundsvallsfjärden, opened in 2014, is one of the longest bridges in Sweden — built to take the E4 around rather than through the city. It's a striking piece of engineering visible from most of the central viewpoints, especially Södra Stadsberget.
You can walk or cycle along the older Alnöbron, the parallel road bridge connecting Sundsvall to Alnön island for the islanders' commute.