56 pages, cave survey (atlas sheets) and colour photo tables; Berlin 2004. S. Arshadi & M. Laumanns. In 2003 a joint Iranian-Swiss-German speleological project firmly established Ghar Katalehkhor (Zanjan province) as the currently longest cave of Iran at 12.860 m, 1.250 m of which are accessible for tourists.This report gives a detailled overview about the physical spelaology and the spelaogenesis of the cave, that has unique spelaothems and fossil deposits.In English language. With an abstract in German. A speleological project in September/Octuber 2003, supervised by the Geological Survey of Iran (GSI), and supported both by the GSI and the government of Zanjan province, firmly established Ghar Katalehkhor (also called: Ghar Kotalehkhor) as the longest cave of Iran at 12.860 m in length. The surveying team consisted of four participants: Mr. H. Akbarzadeh (GSI), Mr. Javad Ashjari (Geological Department of Shiraz University), Mr. M. Laumanns (Germany) and Mr. Reinhold Scherrer (Switzerland). The work within the Zanjan provincial government was co-ordinated by Dr. S. Arshadi (Iran/Germany). Ghar Katalehkhor was discovered in 1965 by mountaineers from Hamadan. It is an anastomotic multilevel cave with a large main gallery, many coulisses, parallel passages, much breakdown and extensive calcite formation, as well as superb crystals that cover complete chaubers for dozens of metres (e.g. the approximately 100 m long "Wedding Hall"). The cave is open to tourists and has a 1.250 m long visitor path that is partly made up of steel bridges. From the terminal point of the show cave the visitors have to walk back the whole distance to the entrance and thus negotiate an underground walk of 2.5 km. Ghar Katalehkhor is developed in Oligocene/Miocene limestone in the northern flank of an anticline. It is suggested that the cave was mainly created by phreatic corrosion in a still water milieu. A spelaogenetic model is presented in this report.
 "Speleological Project Ghar Katalehkhor (Zanjan / Iran), BHB Vol. 12")
