Porsha Stewart revealed on Sunday’s episode of Bravo’s Real Housewives of Atlanta that she thought the underground railroad was an actual train.

Stewart and her reality show co-stars were seen taking a tour of a Freedom Trail in Savannah, Georgia, when the tour guide showed the ladies the ventilation holes that were used to help the escapees breath in fresh air.

"There has to be an opening for the railroad at some point," a puzzled Stewart, 32, said. “Somebody is driving the train. It’s not electric like what we have now.”

Fox News notes Phaedra Parks tried to help her out, letting her know “It wasn’t a train, baby. It wasn’t a train at all. That is just a euphemism.”

Another Real Housewives star, Kenya Moore, said in her one-on-one interview that it was “hurtful” to hear Stewart’s comments.

"It's almost hurtful to me to watch her be so dumb,” she said, Us Weekly reports. She also tweeted after the episode, "When her grandfather fought 4 civil rights that she bragged about, to not know that there wasn't a literal train! #freedomwasnotfree #RHOA.”

image: NBC