PHILADELPHIA (AP) — Tour guides will show you this historic city on foot, trolley or double-decker bus, in a horse-drawn carriage, while riding a Segway or even as you blow a kazoo on a boat with wheels.

But can you believe what they say?

That's a concern of some Philadelphia hospitality officials, who worry the city's most valuable asset — its history — is being tarnished by unreliable tour guides who mix up dates and spice up biographies of famous founders like Benjamin Franklin and George Washington.

"Bring it on," said Jill Lawrence, a Colonial re-enactor who supports the idea. She said many of her interactions with tourists include correcting misinformation they've heard elsewhere — such as flagmaker Betsy Ross, a three-time widow, killed her husbands. Not true.

"These are things we hear over and over," she said. "It would be terrific if we didn't have to correct these rumors all day long."