On the bank of the Mississippi, at the north end of the Stone Arch Bridge, right down at the water’s edge:

The Stone Arch is an old railroad bridge in Minneapolis, at Saint Anthony Falls. It was built in 1883 by legendary fat cat and robber baron James J. Hill, at a cost of $650,000, a nosebleed figure in 1883 ($17.5 milllion in today’s dollars), and to his undoubted displeasure it was referred to as “Hill’s Folly” until its commercial value as a railroad link became clear.
The railroad stopped using it in the 1970s and in the 1990s it was repaired, redecorated and put back into service as a pedestrian and bicycle crossing.
You can still get to this spot but it’s a bit dodgy these days. There’s no trail leading to it, you have to sort of go where you’re not supposed to, and climb down from the road up above. Empty bottles laying around tell you you’re not the first. My future challenge is to get here late in the evening when downtown is lit up.