The Minnesota Zoo turned an old train into a gorgeous, elevated walking path. Now the zoo is busier than ever

The Treetop Trail soars 32 feet above the zoo.

The Treetop Trail, a sprawling elevated walkway that snakes its way around the Minnesota Zoo, presented a unique challenge for the designers behind it. For one thing, it was suspended in mid-air. For another, it was 1.25 miles long.

It’s a challenge that the public, at least, feels the designers met with aplomb. Officials at the suburban Minneapolis zoo credit the trail for helping set an attendance record during the last fiscal year...