There are lots of places in Chicago where you can go, and with a little bit of imagination, be transported to another time.

A stroll along Astor Street takes you to 1930s flapper-era Chicago. A walk down Prairie Avenue takes you to the late 1800s railroad baron-era Chicago. And wander around the West Loop for plenty of glimpses of 1940s industrial-era Chicago.

But have you been to the 400 Block of South Clark Street lately? To us, it’s our favorite Chicago block.

That’s because it transports you back to late 1960s shithole-era Chicago. A time of hot summers, dangerous music, bully cops, cheap beer, aggressive pimps, ghetto sled Cadillacs with curb feelers, crime, grit, and an electricity in the air like the whole city could explode at any moment. This is the dirty Chicago that The Blues Brothers only hinted at, but somehow still glamorized, skinny ties and all.

The west side of the block is a perfect storm of sketchy establishments: A liquor store, a fish and chicken shack, a pawn shop, a payday loan joint, a flophouse, and the secret sauce: A jazz club. Somehow even the cell phone store doesn’t seem out of place among the sputtering neon signs, grimy concrete, and metal accordion storefront gates.

The 400 block of South Clark is the opposite of modern-day downtown Chicago with its dog parks and Trump spires and cupcake boutiques. This block should be a must-visit for all tourists. But only in the dark, and for best effect — after a quick burst of rain on a sultry night to bring out the stench of stale urine.

Then once the tourists have had their fill taking artsy photos of the “Loans on any article of value” sign peeling off the brick facade, have them turn around because they’re standing right underneath a 27-story federal lockup.

Most cities don’t appreciate their landmarks until it’s too late. Chicago should preserve this craptastic piece of its living history the way it does with Frank Lloyd Wright districts. It shows the city how far it’s come in the last few decades, while reminding us that this is still the every-day reality for so many thousands of our neighbors being left behind.