Two Classical Bridges

I came across two bridges with significance derived from ancient Greece. The first is the Eisener Steg in Frankfurt, an old iron footbridge that crosses the Main river in central Frankfurt.

 

The inscription is from Homer's Odyssey: "to many foreigners on a wine-dark sea". No clear explanation of what that quotation is supposed to mean on this bridge.

And then there is this:

 

"This river I step in is not the river I stand in", an allusion to Heraclitus on a bridge that crosses the Don Valley on Queen Street East in Toronto. No more comprehensible -- and why the allusion, rather than the exact quote? -- but equally charming.