So we stopped at Facebook sites in Menlo Park, Google at Mountain View and Apple at Palo Alto. All sites are huge, Google has a whole small town for itself. Interestingly, all places are open. There are no buildings and parks hidden behind high walls or fences, but everyone can look up to them.
The last stop was at Stanford University in Stanford. Again, it is essentially a whole university town, a gigantic area, its own parks, etc. Incomparable with Czech universities.