The ECSS2013 conference venue is Scandic Marina Congress Center. It is located by the sea, right at the heart of Helsinki centre. The venue can be reached by walking from the train station (~20 minutes) or by tram (tram stop is very close to the congress center). The center has also a private parking lot (subject to a charge) for those coming by car.
The address of Scandic Marina Congress Center is
00160 Helsinki - FINLAND
See the address on Google Maps!
The main conference room is the Europaea in the first floor, suitable for 600 persons. Also, a smaller room is reserved for group sessions and press meetings. The registration desk/office, poster sessions and coffee breaks are in the same floor, just outside Europaea.