Cities strongly affected by over-tourism were Beijing, Mexico City, Venice and Amsterdam, but also Istanbul and Florence.
Asia was the strongest source region last year, with 7 per cent more outbound trips.
New Zealand is lagging the international average.
After several years of exceptional tourism growth here, international arrivals grew 3.5 per cent to 3.86 million in 2018, down from 6.7 per cent growth the previous year, according to Stats NZ figures.
Of destination countries, one of the biggest changes was the stagnation of trips to Spain in 2018, a destination that boomed in the recent past.
However, destinations that were avoided by tourists recently are recovering, above all Turkey, with 8.5 million more visitors in 2018 compared to 2017.
Holidays once again outperform business travel, due to the continuous downward path of traditional business trips, while MICE (meetings, incentives, conferencing, exhibitions) trips continued to grow.
Some 38 per cent of international travellers say political instability and terror threats will have an influence on their travel planning for 2019.
Travellers from Asia feel much more affected by terror threats than travellers from other continents.
''In terms of what kind of influence terror threats will have on the travel behaviour, the great majority state that they will choose only destinations, which they perceive as 'safe'." The safety image of most destinations, including Turkey, Israel and Egypt, slightly improved over the last 12 months.