Almost all tourist cities in Italy such as Rome, Florence, Venice, Milan, Naples, etc. charge a local city tax of € 2 - € 5
per person per night that has to be paid to the hotels directly (fee depends on hotel star category).
There are a few other cities throughout Europe such as Barcelona, Berlin, Hamburg, Dresden and as Duvrovnic that also charge a local city tax.
Some airlines and some fares in some airlines require a fee per suitcase.
Baggage fees can be seen during the booking process at the insurance option page below the air itinerary info.
If baggage fees are not part of the fare then these must be paid at the airline counter the date of travel.
Some airlines charge extra fees for selecting seats. This information can be read under 'seats and info' while selecting your flights during the booking process.
Some hotels may charge extra for parking or for the use of resort amenities that must also be paid directly to hotel.
There are some destinations that require a fee to be paid upon departure at airport.