Valley of the Dragons

From Introduction:

"Valley of the Dragons" is a d20 adventure designed for four PCs of 10th level. The characters can be of any race or class, but characters with wilderness skills and knowledge of the planes will be helpful. The characters should have at least one weapon with a +3 or higher enhancement bonus at their disposal or ability to inflict damage not negated by damage reduction. Although designed for 10th-level characters, the adventure is easily adapted for higher level PCs. See the Scaling the Adventure sidebar for ideas and suggestions on accomplishing this. "Valley of the Dragons" is set in the country of Dunreth in the Gothos campaign, but it can be easily integrated into any campaign with some modification.