Portland's Freemont Bridge has been a fascination of mine since well before I moved to the city. I'm amazed by the architecture, the cathedral-like underbelly and its gracefully intertwined layers.
The bridge was completed in 1973, and holds several distictions: The arched portion of the bridge was assembled on nearby Swan Island, then floated downstream and lifted into place. At the time, this was the world record for the heaviest lift.
In addition, the Freemont Bridge is the world's second largest tiered arch bridge, coming in just behind a Chinese bridge over the Yangtzi River. Unfortunately, they do not allow pedestrian traffic on the bridge, denying Portlanders the opportunity to appreciate its' spectacular view at their own pace.
Finally, the Freemont Bridge was an expensive bridge, costing over six times what its downstream neighbor, the Marquam Bridge, cost less than ten years prior. The Marquam bridge was considered a blight on the river by many, so the Freemont Bridge was designed in large part aesthetically, and at a substantially increased cost.