Giant cruise ships will be stopped from steaming past Venice's St Mark's Square under a new deal between the Italian government and Venice officials.
The plan will see the tourist ships re-routed to a nearby industrial port.
After years of debate, it is hoped the move will balance the need for tourism and jobs with the city's delicate ecosystem.
Venice has been a victim of its own popularity, with an onslaught of tourism that has clogged the city's narrow waterways and seen many of its residents depart.
The massive cruise ships dwarf the church towers, the famous views and even sometimes block out the sun.
The plan, to be brought in over the next three to five years, will mean ships over 55,000 tonnes are sent to the mainland's Marghera port.
They would not sail through the Giudecca canal, one of the main waterways through Venice that empties into St Mark's basin.
Environmental groups are unhappy with the plan, however, as they say it still allows polluting ships to enter Venice.
In November 2014 ships larger than 96,000 tons, with a capacity of 3,000 to 3,500 passengers, were banned from the city.
That move came after the Costa Concordia disaster in January 2012, which increased pressure on the authorities to keep liners away from the central Giudecca canal and St Mark's Basin.
Italian transport minister Graziano Delrio said the most recent plan was a "real and definitive solution".
"Let's absolutely keep large ships away from the Giudecca Canal and the Basin of San Marco."
He added: "We also said that during this transitional period, while the Marghera port is being properly equipped, a new
regulation will be put in place by the naval authority.
"This will oversee the temporary passage of large ships with new, more balanced criteria which take into account all landscape, architectural, environmental conditions in order to preserve the lagoon at its best."Let's