The Russian Quantum Center may be offsetting for us foreign people. In the Russian tradition, it has various levels of security people guarding the doors, who won't let you in even if you look an obvious candidate for the building (old professor not speaking the language and uttering words like "Matematiki" or "Kvantovii Tsentr").
From the airport (Sheremetevo), take the Aeroexpress that links to Belorussky Station.
The most convenient access is from the Славянский бульвар metro station (Slavyansky bulvar), taking marshrutka (Маршрутка) n°818 or 523, as well as the Sk-express which is direct.
The marshrutka n°818 used to connect the Kievskii (Киевский) station to both the RQC and its flat (terminus) [1]. However this became disrupted. The bus line n°205 does essentially the same job (with a strange detour through the bus terminal near the end).
You need access with a card or through prior arrangements to enter the Skolkovo premises.
You can't miss the main building, where there are restaurants, cafeteria, hotel, free internet, etc. It looks like this from the RQC itself:
If you get in by taxi, that should sort out your problems with security, as somehow the taxi is easily allowed in (sometimes this is not so straightforward, however). The taxi will then typically leave you nearby the building above.
Essentially, this is a huge building not operating at the full of its capabilities. Most, if not all, the doors of the fancy terrace upstairs, where you are naturally inclined to go, are closed.
You must access by the bottom level, which is somehow less pretty and less engaging as people don't naturally think a magnificent complex has its welcoming doors in the parking. Even there, most doors are still closed. It's not uncommon to find Russian people asking you how to enter the building.
Look for "Pamirs hotel", it's indicated on the walls, somehow you just have to go round till your reach this point:
Some—though not all—of these doors at the end will let you in. You'll then be in the lobby of the hotel, where you'll be free to wander round.
Head first floor (there is an escalator) and enjoy the Clockwork-Orangy atmosphere. A popular meeting place or where to stay in any case is just left when you exit the escalator, at the bar restaurant with hanging circular fluorescent tubes, seen at the end of the picture.
If you are heading for the RQC itself, it is in fact another building altogether. On the panorama below, you recognize the Kubrick building on the right. The RQC is the little blue building on the extreme left. It is cute as well.