What determines workplace culture?

Company policy

Company-sponsored social events (birthday biscuits, christmas parties, etc)
Tea breaks and facilities
Policies relating to internet usage
Flexible working hours
Sick leave, maternity/paternity leave, compassionate leave, etc.
How (or indeed if) good work is recognised and rewarded
Structure of management hierarchy
Attitude of management - separate, "godlike" figure, or "one of us, with a bit more responsibility"?
...?

The surrounding culture

Individuals

...?

Working with different cultures