No ketchup allowed! “Chicagoans take their hot dog toppings seriously: mustard, onions and tomato, neon green sweet pickle relish, a dill pickle and celery salt are must haves. Make sure it’s on a poppy seed bun, but don’t you dare mention ketchup,” said the signage at the interactive and complimentary SKYDECK Museum at Willis Tower, designed to enhance a visit to the famous Skydeck and Ledge on the 103rd floor. I loved the kids’ area of the Chicago History Museum where children are encouraged to see if they can guess different Chicago smells, including hot dogs at Wrigley Field (more than a million sold a season).

And at the Museum of Ice Cream , with more than 14 interactive activities and all the free ice cream you can eat, try the hot dog flavor, complete with bun, mustard and relish. “It was my favorite,” said Graham Avsel, 11, here with his grandparents and younger brother. “It was super gross and super fun to try,” he said.

All eyes were on Chicago this past week as 50,000 people, including thousands of journalists from around the world and protesters from around the country, arrived for the Democratic National Convention. But Chicago is a great bet for a fall getaway when the convention hoopla and crowds are gone. In fact, AAA singles out Chicago as a top 10 domestic Labor Day destination along with Orlando, New York, Boston, Las Vegas, Denver and San Francisco.

Overall domestic travel over Labor Day weekend is up 9 percent compared to last year, whi.