Lairs of the Valiant

From publisher blurb:

Lairs of the Valiant

This volume provides game masters with short, lair-based adventures to enhance their campaigns and breathe life into the monsters that stalk their characters.

Locations and settings are kept relatively generic and are designed so they can easily be placed in ongoing adventures as side quests, obstacles, or for nights when you need a quick encounter in the midst of an ongoing campaign.

The lairs are organized by difficulty, starting with simple but interesting challenges for beginning parties, up to dangerous encounters for higher-level groups.