Athens is the historical capital of Europe, with a long history, dating from the first settlement in the Neolithic age. 
Athens is considered one of Europe's safest capitals; its transportation network is user-friendly; there are numerous museums and archeological sites and hundreds of restaurants to satisfy every taste.
Surrounded by a lining of stunning seas and mountains, Athens is filled with gems just waiting to be discovered. Located at the crossroads of three continents, the capital of Greece with an overall population of close to four million has often been the hub of many cultures. Characterized by a culture and people that are welcoming and hospitable, every visitor just feels at home.
Athens is an ideal congress destination, combining state-of-the-art infrastructure, excellent conference facilities and easy access from all over the world with world-class cultural attractions, modern amenities, diverse entertainment and natural beauty. 

Useful Links
http://www.thisisathens.org/ 
http://www.athensconventionbureau.gr/
http://www.visitgreece.gr/en/main_cities/athens 
http://imanathenian.com/