When I was a teenager we used to go "spelunking" starting below what is now the Burrito Union on 4th street all the way down to Lake Superior.  Some of the tunnels were over a block long.  I certainly would not suggest going in there with children though.

speaking of not-safe-for-children tunnel-type adventures, the old steam access tunnels underneath downtown were great to explore. i used to live in the brownstone apartments (now demolished) on 4th avenue east between superior and 1st street (above the motel). the tunnels were connected to our laundry room, and the one time my roommate & i explored them we ended up somewhere deep, deep in the bowels of downtown. they tunnels kept going, but we chickened out somewhere around the electric fetus.

Yup.  Chester from the lake to Burrito Union.

First as (sometime) parent educator I must say that it is not safe for kids to play in culverts at any time, especially alone.

Second, I can say from experience that my friends and I had hours, maybe even days of joyful/terrifying experiences exploring the miles of tunnels and culverts throughout Duluth's Lester Park neighborhood, most of the time alone, sometimes with flashlights. It was a mini-masculine thing, figuring out who had the guts to do it and go the whole way, etc.  Also the desire to do such a "pointless" thing is a little male - exploring 'cause it's there.  But it is all very awesome, in that same way.  

Third, I am experiencing some really tough days this summer dealing with young parents, i don't know if life is actualyl getting worse or it just feels worse to me.  But this has been a doozie, including one case I worked on today where the young parents are in a situation so bad I bet no one would even think about changing places with them for all the gold in fort knox.  So I really start to lose hope sometimes with how bad things often are.  BUT this post with it's whimsy and lovely photos of the human, childhood experience, and how awesome it is to be a parent has been a great restorative for me.  Thank you double dutch!  

(And remember inspiring as this was, don't let your kids play in culverts alone it's very dangerous! love, Wildgoose)

Oregon Creek tunnel at East 1st Street entrance..
Long with twists and turns. Can do it standing most the way. Not too many bums. Some high brick arched ceilings. Barbecues in autumn.

I grew up on Oregon Creek just south of College Street. You could start taking the tunnels going under Woodland Ave and eventually make your way down to 1st St or Superior St (cant remember where it got too impassable). My favorite time to go through them was during winter. The water would freeze, and the ice inside the tunnel would create the perfect bobsled track. Just had to watch out for giant ice stalactites that would lurk in dark corners after a thaw.

I too used to travel underground via the culverts and I too used to sled inside them in the winter.  My favorite was the one that started up by Marshall school and ended down by the gas station on 6th av east and 9th street.  Well, it was my favorite until my leg made contact with some dislocated rebar sticking out from the side.  I could have poked out an eye!

that brown slime is a little unnerving though...