The conference will be held at the Piperska Muren, a historic meeting center. Both of hotels used by conference participants, the conference center, and most of the evening activities are located within about 2 km of each other, around the center of Stockholm. Nordita itself is located 3 km north of the central area. A map of all the venues is shown here (external link):
The main language is, of course, Swedish. However, nearly everyone is fluent in English (about 90% of the population), so you should have no difficulty communicating with the locals.
The local currency is the Krona or "crowns" (SEK); the exchange rates as of Spring 2015 are about 1 Euro = 9 SEK and 1 USD = 8 SEK. Credit/debit cards can be used just about everywhere and are usually the preferred form of payment. If coming from the USA or another country where credit cards do not have a chip+PIN, you may need to say your card requires a signature when making a purchase; carry your passport with you as identification in this case. Without the PIN, you may run into difficulty using some ticket machines.
The typical high in early June is 20 °C (70 °F) with an overnight low of 10 °C (50 °F); those can fluctuate by 5 °C (10 °F) on a day-to-day basis. Rain is a possibility. Because Stockholm is so far north, the days are long during the summer: there will be 18 hours of daylight each day during the week of the conference.
Arriving in Stockholm
As the main airport, most flights go through Arlanda Airport. The center of the city can be reached via taxi, train, or bus. The airport has several information desks that can help you find your way; free local maps can also be found there.
Taxi. The most convenient, but most expensive option. A journey to central Stockholm costs around 500 SEK and takes about 45 minutes.
Train: Arlanda Express. This high-speed train takes you to the central train station from where you may continue your journey via subway, bus, or taxi (see below). A one-way ticket is 280 SEK, roundtrip is 530 SEK; discounts are sometimes available when traveling with others. The trains are frequent, running every 15 minutes for most of the day. Follow the signs located throughout the airport. Tickets can be purchased via ticket machines or from one of the airport information desks. The journey takes 20-25 minutes.
Bus: FlygbussarnaA frequently running bus shuttle that takes you to the central bus terminal from where you may continue your journey via subway, bus, or taxi (see below). Tickets are 119 SEK one-way or 215 SEK roundtrip when purchased via the ticket machines at the airport or bus terminal. The tickets can also be purchased online for a slight discount (99/198 SEK). When purchasing online, you need not print out the ticket if you have a smart phone: simply show the QR-code from your PDF ticket on your screen. Tickets are valid for 90 days. These buses are also frequent, running every 15 minutes during most of the day. Follow the signs for Flygbussarna pickup locations and be sure to take the one that goes to "Cityterminalen" (the busiest one). The buses and stops are easily identified by the rainbow insignia they use. The journey takes 45-60 minutes.
Early morning arrivals/departures.Between 1:00 and 5:00 in the morning, Arlanda Express and Flyggbussarna may not be operating. However, the city bus line 592 runs hourly during these times. Taxis are also available.
Stockholm Central Train (Centralstation) and Bus (Cityterminalen) Stations
The main train (Centralstation) and bus (Cityterminalen) stations are located adjacent to each other in the central area of Stockholm. They are conveniently connected by an underground passage to one of the main subway stations (T-Centralen), through which all the subway lines pass. Numerous local bus lines are easily accessible; see below for public transit details. Taxis can be found at all hours in the designated areas (follow the signs).
Public Transportation (SL)
The public transportation system (SL) is composed of bus, subway (tunnelbana, or T-bana), and local commuter train (pendeltåg) lines. In any journey, you may transfer among these various modes for up to an hour after you first start your journey.
To use the public transit system, you must purchase an SL Access card (20 SEK) and then purchase tickets to be stored on this electronic smart card. You may purchase passes for 24 hours (115 SEK), 72 hours (230 SEK) or 7 days (300 SEK), or you may simply place credit on the card and pay fares for each journey (36 SEK for a 1 zone journey, which encompasses nearly all locations you are likely to go). SL access cards can be purchased at an SL customer service center (one in Centralstation in T-Centralen, the central subway station) or at many convenience stores (such as Pressbyrån). Credit and tickets can then be purchased at the same locations or at machines located at each subway & commuter train station. Note that you cannot purchase tickets on a bus: you must have credit or a ticket loaded on your card beforehand. To use the card when boarding a bus or entering a subway/commuter train station, just swipe your card over the light blue reader. You do not need to swipe out for any of these.
The SL website has a journey planner on it's front page. All the public transit schedules are also available through google maps, which may be a more convenient journey planner. All subways and some bus stops have displays showing real-time information.
This conference center is located on Kungsholmen ("King's Island"), about 1 km west of the train station. From the central train/bus station, it can be reached via taxi, bus (40 & 52 are the closest, 1 & 3 are not much farther), or a 10-15 minute walk. The Amaranten hotel is next to the the conference center, which can be most easily reached via a back entrance to the hotel. From the Grand Hotel, Piperska Muren is most easily reached by taking either of the blue line subways from Kungsträdgården to Rådhuset.
For those arriving from North America, note that a "double" room refers to a room meant for two, not to the bed size.
Clarion Hotel Amaranten. Located adjacent to the Piperska Muren conference venue. Piperska Muren can be easily accessed via a rear entrance to the hotel. If arriving from the train/bus station, local buses 40 & 52 are the most convenient, while 1 & 3 are also close (there are even more lines if you find a transit map). Otherwise, it is a 10-15 minute walk (0.8 km). Despite appearances on a map, the subway is not more convenient than just walking (the surface exits do not show the actual locations of the subway platforms).
Grand Hotel. Located on the waterfront, facing the Stockholm Palace ("Kungliga Slottet"). From the train/bus station, a taxi is most convenient. Otherwise, either blue line train can be taken from T-Centralen to Kungsträdgården (one stop). Bus line 65 also works. To travel to/from the Piperska Muren conference venue, take either blue line train from Kungsträdgården to Rådhuset (two stops).