National Steel Car began in Hamilton 101 years ago. It does just what its name says. It makes cars out of steel and sells them nationally – and around the world.

But these cars ride on rails. That market experiences great ups and downs, but numbers are supposed to be pretty good right now. As a result, there are more than 2,000 on the company’s payroll today. That would make it one of Hamilton’s largest employers.

Even so, you don’t see National Steel Car in the news much. That is the way the company likes it.

There is, however, a beautiful mystery out there. Let’s try to pull back the curtain a little.

National Steel Car is big, some two million square feet of plant on 75 acres by the harbour. On the company’s website, you’ll see images of a thoroughly modern operation. There are artistic touches too, a line of stacks coloured like a rainbow.

The entrance to this complex is plain, just a boxy guard house by the side of the front drive. At least that’s the picture shown on the website.

But there at the north-east corner of Kenilworth and Burlington is a sight to behold. Amidst the grey of industrial Hamilton sits a bright-yellow, shiny-steel Art Moderne entrance to old National Steel Car. It is a beautiful slice of ‘30s-style architecture.

And here’s the mystery. This entrance has been in place for at least three years, perhaps longer. However, for some reason the structure remains unfinished. There are barricades, and a sign that says Construction Area – Do Not Enter.

This is clearly a company that cares about how it looks. Why the messy front door for all this time? Some kind of dispute with a contractor? A change of heart?

We need to go right to the top. That would be Greg Aziz, chairman and chief executive officer of National Steel Car. But I warn you, we may run into problems.

Fifteen years ago, when working for The Spectator, I started getting calls about the new Canadian flag at National Steel Car. It was huge, had to be Hamilton’s biggest. So I called Aziz back then.

"Tell me about the flag," I said.

"Why would I do that?" he answered.

"Why wouldn’t you?" I replied.

"Because we don’t like publicity here," said the chair. End of conversation.

I’m sure we’ll do better this time. Let’s try the personal touch.

I’m at the guardhouse and ask the fellow if I can talk to somebody about the shiny fenced-off entrance. He says that would be a question for Mr. Aziz and suggests I phone to make an appointment. He writes out the number.

I do a short u-turn, park by the artful entry, and call. Aziz answers.

I introduce myself. I don’t mention the old conversation about a flag, and I’m sure he’s forgotten it.

I tell him that the yellow entry is beautiful. "Who designed it?"

"You’re talking to him," he says.

But why is it still not open, I wonder. "This is a very capital-intensive business," he says. "There have been other priorities."

It’s hard to imagine that the cost of finishing touches for this Art Moderne gem would trouble a company that spent $350 million on plant improvements over the last 15 years. I don’t mention that to Aziz.

But I do tell him I’m parked on the property and ask if I could come in for a few minutes. "I don’t want to be interviewed," he says.

But it’s already an interview, I tell him.

"OK, we’re done," he says. And he hangs up the phone.

For now, I’m afraid, this one stays in the Unsolved Mysteries file.

Paul.Wilson@cbc.ca | @PaulWilsonCBC

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