> A cairn is a mound of stones erected as a
marker or a memorial. A dolmen is a mound
of stones erected as a marker or a ... wait a
minute. Um. Oh. I think a dolmen marks a
tomb. Anyway, we didn't see the cairn at all.
>
> -Faux "which means 'rock'" Pas

Dolmen: a prehistoric monument of two or
more upright stones supporting a horizontal
stone slab found especially in Britain and
France and thought to be a tomb

And a cairn is exactly what you said.

Gri"thank you, m-w.com"shny