Can you have too much of a good thing?

This is the issue plaguing one of Europe's biggest tourist cities, Barcelona.

Around 20 million tourists visit Barcelona each year, in stark contrast to the city’s population of just 1.6 million.

The increase in tourist numbers has also led to a decline in that resident population.

The city centre’s residential population has declined 11% in the past four years. A major contributing factor is the amount of apartments being rented out to holidaymakers.

Barcelona City Council is attempting to please both sides of the debate, by promoting the peaceful coexistence of locals and tourists alike. Employing local mediators is one of the services used to help solve issues that arise between residents and tourist flat owners.

Mediators say some of the most common complaints include loud noise from late night parties and messy communal areas including lifts.

Although the mediation service has only been running for six months, 400 cases are already on the waiting list.

With summer tourist season already in full swing, this number is only expected to rise.

Watch Euronews' latest report in the player above