The International Tunnelling and Underground Space Association held its forty-first meeting in Dubrovnik, Croatia, from 22 to 28 May 2015, in conjunction with the World Tunnel Congress 2015 "Promoting Tunnelling in South East European Regionion" organized by ITA and the the Croatian Association for Tunnelling and Underground Space - ITA Croatia..  More than 1550 persons participated in the Congress. 57 of the 73 Member Nations participated or were represented in the General Assembly.