Venice announced on Thursday that it would introduce a fee for day tourists to enter the city's overcrowded historic center for 29 days next year as it seeks to come to grips with over-tourism. 

Day visitors will need to pay five euros ($5.45) to enter the city center between 8:30 a.m. to 4:00 p.m. during the peak tourist season from 25 April to 5 May. 

The fee will also apply for the rest of the weekends in May and June, as well as the first two weekends of July.

Authorities have debated for years — without taking concrete action — over how best to regulate the millions of visitors to the famous watery city, who come anxious to see sights including St. Mark's Square, the Rialto Bridge, and its countless picturesque canals.

The ticketing plan had been repeatedly postponed over concerns it would seriously dent tourist revenue and compromise freedom of movement.

But city authorities finally decided earlier this year to push forward with the experiment after UNESCO warned it could list the city as an at-risk world heritage site.

"Venice is the first city in the world to introduce such a system, which could serve as a model for other fragile and delicate cities that must be protected," Mayor Luigi Brugnaro said in a statement.

But he called it a "first step" rather than a "revolution" and said authorities stand ready to make changes to ensure it works.