Intelligence committees in exchange for immunity, but committee leaders declined the offer.

Flynn was fired from his post as national security adviser in February for misleading Vice President Pence and other White House officials about conversations with Russian Ambassador Sergey Kislyak. Russian officials reportedly bragged during the 2016 campaign that they could use Flynn to influence Trump in the White House.

Flynn last year declined to say how much he was paid for the speech.

"It was an interview in front of the forum, probably 200 people in the audience. My purpose there was I was asked to talk about radical Islam in the Middle East. They asked me to talk about what was going on in the situation unfolding in the Middle East," he said.

— Updated at 5:33 p.m.The exhibit, on loan from the Museum of Leonardo DaVinci in Florence, features more than sixty handcrafted replicas of the Renaissance artist's creations, including "The DaVinci Mechanical Lion," a gift to the King of France that's making its first appearance in North America, and a near-life-sized replica of "The Last Supper" on display for the first time anywhere.

"We are so thrilled to have our exhibition at the Denver Pavilions," says Ali Rodgers, museum curator. "So far, everyone has been embracing our exhibit, and out of every state, Colorado has shown the most interest."

The exhibit is divided into four sections: war machines, flying machines, nautical and hydraulic machines, and mechanics. You can operate many of the replicas of the 500-year-old inventions, which are accompanied by notes and illustrated panels.