There is a huge selection of hotels in Athens to suit all price ranges. Delegates will be accommodated in hotel rooms located in the historic centre of Athens, in short (walking) distance from the main venue of the conference. Reviews and prices are available on https://whyathens.com/hotels/ and make bookings through expedia.com or booking.com.

Delegates travelling from outside of the EU, should also check the visa status regarding their trip to Greece, and any special arrangements that might be necessary to be made. Most valid information can be found in the website of the Greek Ministry of Foreign Affairs.
Greek Ministry of Foreign Affairs – Visa Information
and
Greek Ministry of Foreign Affairs countries that require or not visa