|How to get there|
In the map below, the letter B denotes the main entrance to the math department (Lindstedtsvägen 25).
Go to Lindstedtsvägen 25 and enter the math department main entrance door (it should be unlocked). When you go inside, there is a staircase on your left side. Go two floors up. (Maybe surprisingly, when you get in to the building, you are on the 5th floor, after the stairs, you should be on the 7th floor). After the staircase, turn left, and immediately again left, and go through the first glass door, which is not locked. Right after that, seminar room 3721 is on your left.
The subway station Tekniska Högskolan is just outside the campus:
Visa större karta
From Värtahamnen: Take the subway from Gärdet to Östermalm's torg (towards T-centralen or Norsborg), and change there to the subway towards Mörby. Step off at Tekniska Högskolan. (Please notice that both these subway lines are marked with red on the subway line map, but they are not the same line.)
From Viking terminalen: There is a bus stop near the terminal (when you get out of the building, look forward over the parking area, and you should be able to see a bus stop). However, it is not possible to buy a single ticket from the bus. Cellphone ticket or förköpsremsa, etc are possibilities. However, it doesn't take long to walk to Slussen. There you can buy tickets, and take the subway towards Mörby. Step off the subway at Tekniska Högskolan.
From Central railway station/T-centralen: Take the red line towards Mörby. Step off at Tekniska Högskolan.
From Arlanda: Take Arlanda Express (train, 240 kronor) or Flygbuss (99-119 kronor depending on whether you buy the ticket in advance on the internet or from the bus) to the centrum of the city. It is the best bet to assume that they only take a credit card on the bus (no cash or Visa Electron). You will arrive either to the railway station or to the City terminalen. They are close to each other. Nearest subway station is T-centralen.
From Skavsta: Take Flygbuss or Ryanair's own bus to the centrum of the city. You will arrive to the City terminalen. Nearest subway station is T-centralen.
Förköpsremsa is cheaper than to always buy tickets. Förköpsremsa means a ticket with 16 stripes. When you travel, the driver (or the person in the glass box in the subway station) will stamp two or three stripes according to the station you are traveling to. It is two almost always. Basically one Förköpsremsa is 8 trips, and the price is 180 kronor. There is one hour time to change. More than one person can use the same förköpsremsa.
It is worth knowing that if the glass box person is missing from the station, you are still allowed to go to the subway without stamping your förköpsremsa, but you have to have a valid ticket (in other words, a valid single ticket, or a förköpsremsa which still has unstamped stripes, or a Stockholm card, or something similar).
Single tickets are also an option. Buy from automates. It is not possible to buy a single ticket from the bus driver. However, it is possible to use cellphone tickets.
There are also 24-hour tickets, and similar. Those are cheap if you really plan to travel a lot.
The easy and standard ways to get to Stockholm from Finland is to take a plane or a boat.
Blue1 has regular service from Helsinki, Tampere, Turku and Vaasa to Stockholm.
Viking Line and Silja Line have regular ferry service to Stockholm. If you want to save money, pay only for a bed, not for a full cabin. (When you make your booking, look for female/male beds.)