We are pleased to invite you to participate in and contribute to the 20th International Diatom Symposium (IDS2008). IDS2008 will be held on 7-13 September 2008 in Dubrovnik. Dubrovnik is an old city on the Adriatic Sea coast in the extreme south of Croatia. It is one of the most prominent tourist resorts of the Mediterranean. Dubrovnik is nicknamed "Pearl of the Adriatic" and is listed as a UNESCO World Heritage Site. Its population was 43,770 in 2001.