People tend to check in during these times:
Building 1 (Itämerenkatu 11-13) is now closed for good; work continues for now at Building 2 (Itämerenkatu 9). After the summer, Otaniemi!
Quiet room on B2 is amazing. Relax for 20 min in a massage chair, listen to music of the nature.
The toilets make an excellent getaway from loosing your market share with lackluster devices. :)
Try a wild mushroom soup in Sodexho restaurant
Attend a meeting
Open spaces and good coffee. Avoid eating here.
Do not talk to the natives, they are all part of some sarcastic open source cult. Use of protective gear is adviced indoors.
Nice short term workspace up on the 7th floor.
Nice cafeteria, good lunch.