The Mouth of the Shadowvein is an OSRIC(tm) module designed for 6-10 adventures of levels 3-5.
The depths of the underearth weigh heavily upon the party as they delve deeper into the cold, hard stone. Every river has an end, even those that never see the light of day. Many adventures behind, the party continues to find the mouth of the Shadowvein. What lies ahead is surely dangerous, but the lure of the deeps is strong with gold and magic.
I'm very pleased with this module and I think it contains some of my best work, so I hope you decide to check it out. In particular, I think the large underground fungal cavern should be supremely portable into any campaign.