One more reason to get outside this fall: The rascals of Nordic folklore lurk in a Chicago burb.
Morton Arboretum trolls
Morton Arboretum trolls

Stay vigilant during your next trip to The Morton Arboretum near Chicago in Lisle: Giant trolls have surfaced in its forests. Danish artist Thomas Dambo used reclaimed wood to create the mischievous creatures (on display now through at least summer 2019), reimagining them as protectors of the forest.

Morton Arboretum trolls
This guy, Rocky Bardur, doesn't hide like the other trolls. And he apparently would prefer that you ride your bike.

The fun begins with finding the trolls. Seeing their attempts to foil pesky humans keeps the journey upbeat, even with its deeper message about forest preservation. Good to know when you go:

They're huge. Multiply your height by three or four and you'll get a sense of how giant these six trolls are. Fallen trees and battered boards make up their bodies, allowing them to blend into the arboretum.

They're secretive. Dambo has created troll sculptures around the world, but this marks his first large-scale installation in the United States. To add to the trolls' mystery, he constructed a "secret troll habitat," complete with a giant toothbrush and other troll essentials, deep in the 1,700-acre forest.

They catch and release. Some of the trolls are armed with trapping devices. Look for one clasping a rope connected to a wooden crate propped up by a stick. Another holds a long rod with a net that visitors can climb into for the perfect troll-capture selfie.

They love riddles. Some trolls are easier to spot than others. Visitors can use a troll-hunter's handbook to solve written clues that lead them to the creatures. You also can cheat by using the arboretum's standard map, but why do that when acres of fall foliage beckon?

Toast the trolls while learning more about oak trees and the wood that's key to making whiskey at an afternoon tasting and stroll through the grounds.