The Fredericton Railway Bridge is a converted former railway bridge that now serves as a pedestrian and cycling crossing over the Saint John River. Walking across it offers good views up and down the river, and on a clear day you can see the city's Victorian skyline — the cathedral spire, the old legislative building, the waterfront park — from a perspective that you can't get from the riverbank.
The bridge is part of a larger trail network that links both banks of the river through Fredericton, and it's a good option for a walk or bike ride that gives you a feel for the city's relationship with the water. The river is wide and slow at Fredericton, and the views are particularly fine in autumn when the surrounding trees turn.