The secrets under the Capitol

• The tunnels were originally used to transport coal to keep the domed building heated, state patrol trooper Allen Minturn told Axios Denver during a brief tour.
• Their main use now is for infrastructure like electric wiring and pipes, and the enclosed passageways connect to several nearby buildings.

Heavy vault doors, once used by the state treasurer to store precious things, now protect several, stacked boxes of paperwork in one of the underground rooms.

What they're saying: "People do get lost down here, once in a while," Minturn said.

• He's heard the lore of hidden treasure: As the story goes, a worker there was paid in silver coins, which he then stashed somewhere underground.
• Another legend suggests the tunnels were where the heads of the Espinosa brothers, serial killers in the mid-19th Century, were kept until being discovered by interns.

Yes, but: Staff doesn't offer tours, and photography isn't allowed for security reasons.

• But you can walk the steps into the dome with a traditional, above ground tour.