Travelers to Europe (Google "Visa" plus the names of other countries of interest) from Australia, Canada,
Japan, New Zealand and the United States:
Visitors must have a valid passport.
They don't need a prior visa for a visit three months or less.
A visa is added to the passport on arrival.
For stays in Europe longer than three months, visitors must check the
Schengen Rules (EU Summary.) It might be necessary to leave the
Schengen Area for 3 months or get a longer visa from one of the
Schengen countries. Check the visa requirements of the country itself.