Alnön is the forested island directly east of Sundsvall, connected to the mainland by the Alnöbron road bridge — a crossing that takes only a few minutes by car. Despite its proximity, the island feels removed from the city: quiet fishing villages dot the shoreline, sandy beaches face the Gulf of Bothnia on the eastern coast, and the interior is covered in pine and birch forest laced with flat, well-marked hiking trails. A slow circuit drive around the island's 40 kilometres takes a comfortable afternoon.
The geology sets Alnön apart from its neighbours. The island is the surface expression of a single ancient volcanic intrusion — an alkaline complex that has yielded carbonatite and several minerals not found anywhere else in Scandinavia. Geologists have been drawn here since the 19th century, and a handful of roadside outcrops are signposted for the curious visitor.
The island's oldest building, Alnön Old Church, dates from the 12th century and stands intact at the northern end. Its Romanesque sandstone font, carved by a sculptor known only as Sighraf, is one of the finest pieces of medieval stone carving in the region. Combine a visit to the church with a stop at one of the seasonal waterside cafés before completing the circuit back to the bridge.