Junk hunter

There's Beaver Bay and that guy in Soup Town- neither are true flea markets (a single seller does not a flea market make). There have been flea markets set up at the Carlton County Fair and the Old Time Tractor fests in years past.

No.  And there is nowhere to get frozen yogurt by the lake.  Get used to it.

Though not technically a flea market, there's a lot of cool stuff at the "Retro" antique store on the 100 block of 1st St E downtown.

They call them antique stores here.

Check out the antique mall in Canal Park! Or Central Sales, if your tastes are more manly

Sellers Auction on 21st W and 3rd street holds auctions every Monday.  That place is a trip!

Ever wonder why they are called flea markets?

The term flea market is a translation of the French marché aux puces, literally market with fleas, an open-air market where second hand goods are sold. 

From George S. Dougherty's 1922 In Europe:
It is called the "Flea" Market because there are so many second hand articles sold of all kinds that they are believed to gather fleas.
Some suggest that the term is also influenced by the fact that such markets are not fixed and jump around like fleas. While this may be a characteristic of the markets, it does not appear to be the origin.

(Source: Oxford English Dictionary, 2nd Edition)

Flea market is different than an antique store. But the auction house intrigues me...worth a trip, eh?

The auction house is worth the trip, if nothing else for the people watching aspect.