The events will take place at the Stockholmsmässan in Stockholm, Sweden
http://www.stockholmsmassan.se/?sc_lang=en
The IJCAI and EUAI conferences, which are taking place in the same building as the ICGA event, have deals with a couple of local hotels. Visit https://book.passkey.com/event/49566506/owner/49181/home
for booking at one of those hotels. The main conference hotel is the Scandic Talk, which is attached to the same building as the ICGA event. The cheapest room rates (room without a window) from that web site average 1,890 Swedish kronor per night, which is roughly USD $225 or 182 Euro. A very wide range of hotels and room rates, with quite good deals, can be found at