at least 25 years ago, maybe 35, we were in this absolutely nowhere in place in france buying lunch products, and the owner behind the counter asked if we would like to tour the factory where his brother worked. Polite said of course. sent us to the Chanel factory. same place also made shallamire, which my wife used. they also made about 100 other stinkers. did the stinking tour. then they gave my wife samples. fortunately that was before tsa, so we hauled them all home. i think she still has and uses the samples.

Harpoon Brewery in Boston.

Cadbury factory in Dunedin, New Zealand. The chocolate waterfall isn't exactly Wonka-esque, but still impressive.

another vote for the Boeing at Everett - and also whilst I was in Seattle I enjoyed the underground passages tour - OK touristy but found it interesting.

Volkswagen Autostadt in Wolfsburg. Definitely a must see for any car enthusiast.

The Gibson Guitar Factory in Memphis is great if you like guitars

+1 on boeing even with the 787 debacle. We went many years ago and the assembly floor was just amazing

Also even though I'm not a beer drinker. Budweiser in st louis and speights brewery in Dunnedin new Zealand were both great tours and iconic symbols of their respective cities.

Enjoyed this as well. Liked the old delivery vehicles in the yard.

If you're ever in St. Louis, this tour is highly recommended; it is very well run and classy. The architecture, history, and automation are stunning, and the Clydesdales and their stables are beautiful.

Oh, and that 2-drink limit at the end of the tour is really just a suggestion.

The Jack Daniels Distillery tour in Lynchburg, Tenn. is at least worth a detour -- though they are in a dry county and you won't imbibe.

BMW factory tour and museum in Spartenburg, South Carolina. It's not far from GSP (Greenville-Spartenburg) airport. I think it requires a reservation.

Someone else mentioned their European delivery program. Mercedes near Stuttgart does something similar. If you purchase a car, you get a special VIP tour and are introduced to your vehicle by a technician at the end. You're also invited to lunch in their nice dining room, with alcohol-free wine and beer.

I'll also add my vote for the Bacardi rum tour in Puerto Rico.

They're not exactly factories, but many stock exchanges and similar institutions (if they haven't yet switched to a purely computerized system) offer tours and have museums. NYSE and CBOT are the obvious ones, but I enjoyed Tokyo because of its dated and somewhat culturally-driven view of personal finance. (Your stock broker is your friend, concerned about you,.....)

Other favorites include Hershey's Chocolate (Pennsylvania), various auto companies (Buick, Ford, now MB in Tuscaloosa, Alabama), Heinz foods (soup), the USA Mint, plus the CRJ assembly and interior design and installation facilities (for private planes) that we visited on SMD3 and airport food service and baggage handling areas. All but the last ones are public tours. However, in some places you may be able to get access to a less public tour behind the scenes. For example, I've been down on the trading floor at the NYSE, which gives a different impression of the action than what you get from the viewing windows. The same for technical tours at Boeing.

in yogyakarta, indonesia, you can "tour" (more like visit) a silver or batik "factory." i do not recall if i bought anything, but i would not be concerned if i had since i went with a local friend.

Speaking of cava wineries, Codorniu is in Sant Sadurni d'Anoia, the same town as Freixenet, and also has a great tour. They take you down into their cave system where they do the aging, where you ride on this cart train through tunnel after tunnel lined with cava. Most of the tour is underground. There is a tasting at the end. The main building was done by a Gaudi contemporary in the modernist style.

I didn't have time for the Freixenet tour but they have some cool old custom cars outside.

Sam Adams Brewery in Boston does a good tour. First hour is learning about their beer, second hour is drinking. The room is set up like an Oktoberfest tent - long tables. Great spot to spend a few hours if you have the time in Boston.

Louisville Slugger (Ky) museum is cool if you like baseball. Watching the special order bats on the lathe was rather cool. Not sure if they still give them out but we all got small souvenier bats. Fortunately, we'd planned ahead and checked one bag to get them home. There was a entire bin of them at TSA.

This is an awesome tour. Lots of memorabilia, like a mini hall of fame. Highly recommended.