Any suggestions on hiding my speaker cable that runs in front of my fireplace?

I have an over-the-mantle mounted TV. The speakers flank the fireplace with the receiver to the right side. I HAD run my TV power and HDMI cable through the wall, but long story short, I'll be re-fishing them both through.

My question is -- any recommendations for hiding my left channel speaker cable? I'd really hate to bore a hole into the floor or cut through studs for ONE speaker wire. I COULD potentially have it go through the floor where my rear speaker cables run (assuming the hole can fit another 16 gauge speaker wire through it), take out the drop ceiling panels in my basement and then bore back up and have it exit on the left side of the fire place somewhere...but again, that would involve tearing up baseboards, boring holes in the wall and putting some kind of cable "outlet" panel.

So I'm thinking the easiest and cheapest way -- by far -- is just to keep the speaker wire OUTSIDE of the walls/floors. Is there a good way to hide it? i.e. a moldable plastic "runner" that I can flex to the bottom of our fireplace? (PS -- I can get rid of the "bead board" in front of the fireplace. We had it there when our daughter was young so she didn't get in it). There is also a good six or eight inch piece of tile at the base of the fireplace, so the cable and/or "cable hideaway" wouldn't be right up against any super hot surface.

Thanks for the suggestions, guys...

My center channel already has a clean run through the wall. It pops out an inch above the mantle. The two black cables you see to the right of the mantle are the HDMI cable and the TV power cable. I resolved those last night, so they are hidden once again.

It just seems like a lot of work to tear apart baseboards/fireplace frames for one speaker wire. In my mind, I was thinking there might be a moldable plastic "runner" that is only like an inch wide or so, preferably in white, that I could just run it around the frame of the mantle/fireplace with the wire underneath it.

Not saying the ideas above are bad...they are getting the hamsters moving in the wheel.

I came up with a temporary solution -- but a simple revision might make it "permanent". We're talking about 10 cents worth of "parts" and just a few minutes of labor.

Instead of running through a channel along the baseboards (and somehow jumping it to the other side), I ran it up the left side of the fireplace frame, turned the corner and ran it under the lip of the mantle. Came down the other side (which nobody can see from any normal viewing angle) and it disappears behind my right speaker and/or the speaker stand. Currently, it's just clear tape holding it up. I'm going to try and find some white (electrical?) tape that would be a bit stronger/more permanent yet still blend in.