From the publishers blurb: Gunderholfen… Ancient, abandoned dwarf hold, battleground of arch-liches, cultist base, wizards’ playground, heroes’ bane and treasure-seekers’ tomb. Gunderholfen is a classic, old school exploratory sandbox-style mega-dungeon consisting of ten levels, a mini-campaign setting and one demi-plane. This mega-dungeon and mini-campaign setting is designed for character levels 1-10+. It is compatible with any OSR system. Play it as an integrated, complete mega-dungeon campaign or just pick out individual levels to run as separate dungeons. Gunderholfen includes the following: 10 main dungeon levels consisting of 22 sub-levels and numerous sub-areas, with approximately 930 keyed locations, all detailed in 40 maps. 1 demi-plane level. A mini-campaign setting insertable into any existing campaign that includes a detailed overview of Longfelt, a nearby city complete with NPCs, including possible patrons for PCs, places of interest, encounter tables and rival factions. 32 encounter tables with full monster stats for each level of the dungeon and the surrounding lands. Extensive ready to play lists of NPCs including 10 pre-generated NPC parties that can be used as foes or allies. 1 fully detailed mini-side adventure. A brief overview of the history and background to Gunderholfen. Rules for a new class of priest including 18 new spells. Many new monsters and magic items.