The former Spinni-reservoir is about 1200 meters southeast of the spinning mill aside the Lorze in Baar. The reservoir was built in 1890 and was used as that until 2004. Thanks to the initiative of the owner, Korporation Baar-Dorf, this place will be revived and open for public for the first time. A new 17 m long access was built in the southwesterly corner of this underground construction. This plain tunnel leads the visitors into an impressive and monumental column hall, that presents itself like an ancient cistern – a great monument.