From the publisher:
Ancient gods, giants, fey spirits, and a mysterious fog-veiled isle where a long forgotten dark magic lurks... Based loosely on ancient Celtic mythology, Tribes of Danu is a series of OGL 3.5 Adventure Modules. The modules and expansions are designed so each may function as stand-alone adventures, but are intended to be played as a serial.
An adventure module for 4 characters of 1st level.
From the publisher's twitter account:
"Tribes of Danu: "Heart of the Neolith" Adventure Module available on 06/15/2009. $15.00 USD for Print Version or $9.00 for PDF Download."
A Celtic themed 1st level adventure in which the heroes must rescue a Celtic prince.