CBC's Andrew Chang in Rio: the security at the Olympics

In Sochi, we called it the "iron ring" the security perimeter established around the coastal cluster, where almost all of the indoor winter events were happening.

Here in Rio, though, I think of it more as a "metal maze."

One of the great ironies of working in the heart of Rio's main Olympic Park is that it can sometimes feel next to impossible to do something as simple as walk from one venue to the next.

Journalists are meant to take internal shuttles from venue to venue, but if you imagine all the venues forming roughly a trianglewhere ticketholders can move freely on the inside,the media buses operate on the outside.

• CBC'sAndrew Chang shares his Rio experiences

And though the media have very privileged access to the best parts of every venue,we're usually restricted in how far outside of those "best parts" we can go.

Trying to go from outside the triangle to inside is almost never straightforward, and almost always counterintuitive(i.e. if you want to go south, head north, spin three times, click your heels, then head south).

Big brother is watching

Then there's the actual security.

There's more than 200kilometres of security fencing in Rio, and thousands of military personnel tasked with controlling who goes where.

The difference between Rio and Sochi, though, is that security here makes it painfully clear that they're watching you.

In Sochi, security rarely dressed the part; they sported big, civilian winter jackets made to blend in with the thousands of volunteers.

It was only by learning how to identify them that you could figure out who was heavily armed, and who wasn't.

But here in Rio, guards wear army-style combat fatigues. Their weapons are always visible. And depending on how significant a pointofentry is, some personnel will have bigger guns than others.

Trying to talk to them is a bit hitormiss.

Some will acknowledge you if you acknowledge them. Others, you just have to look at their eyes to know they are not to be trifled with, and certainly not interested in talking to you.

Nonetheless, I did decide to ask a few guards if I could take their photos. They all shot me down.

Figuratively, of course.