What's that smell

We are staying at a hotel in Matsue.  It is a pretty nice hotel, but the stairs have a distinctive smell.  

I'm on the sixth floor, which means that I use the stairs for going down unless the elevator is on my floor when I get there; and I use them for going up when I'm feeling not too sweaty.  Altogether, this means that I keep smelling the stairs.  

It's an old moist smell -- familiar but I have trouble placing it.

Until I don't.  It comes to me on the third day, as I am going jauntily down the stairs. This is the smell from my Grandma's basement!

"Grandma?" I ask when I realise this, looking around.

Of course, she is not there.  Indeed, there are no sweet tiny old women around, Norwegian or otherwise.  

But my Grandma's charmingly uncharacteristic distrust of the Japanese starts to make a little more sense.