Calgarians will get a chance Saturday to get an up close look at the city's most expensive road project ever.

The city is holding an open house for the new airport tunnel and Calgarians are invited to stop by and take a peek. Construction on the tunnel started three years ago and it has cost $300 million to complete.

"This will be the one and only time where people really get a chance to walk around inside the tunnel," said Mac Logan, head of Calgary's transportation department. "They can talk to the folks that built it, get an up close look at the different systems."

There is no parking at the site so visitors are encouraged to take shuttle buses from the McKnight-Westwinds C-Train station.

The open house starts at 11 a.m. MT and runs through 2 p.m.

The tunnel will open to regular traffic at 5 a.m. Sunday.