Here's my two-bits:

In my experience, Kundalini is an energy that's generated at the base chakra and travels upward. From my feeling-experience of it, I don't know if I can say it's located anywhere. With the few experiences I've had with it, it felt like it was generated (or, I suppose, you could say "awakened") when my base chakra was especially active and spinning quickly. I suppose you could say it waits at the base to be awakened, but that seems like metaphor to me.

I guess what I'm saying is that Kundalini, to me, is more of a potential, a happening, a mode of energy, a certain peak experience of one's own energy, than it is an elixir waiting to be tapped. And yet...the feeling of Kundalini is a very specific feeling... To me it feels dense, almost physical.