Italy's Pompeii to cap daily visitor numbers to 20,000

The ancient Roman archaeological park of Pompeii in southern Italy says it will cap daily visitor numbers at 20,000 as a response to its surging popularity.

The change, effective from November 15, comes after a peak of more than 36,000 daily entrances on a free-admission Sunday, the park said in a statement on Friday.

The park's director, Gabriel Zuchtriegel, said that reducing human pressure on the ancient site was important for conservation and safety reasons.

The new limit follows attempts by other tourist hot spots to control the number of visitors, including Venice in Italy, with its entry fee system.

Last year, Pompeii had more than four million visitors, up 33.6 per cent year-on-year, translating into a daily average of around 11,200 people, culture ministry data showed.

A spokesperson for the park said the 20,000 daily figure had been surpassed only during free-admission Sundays and on three or four normal paying days.

Entrance to Italian museums is free on the first Sunday of the month. A regular ticket to Pompeii otherwise starts from 18 euros ($A29).

The site is an archaeological wonder, showing the remarkably preserved ruins of a once-thriving city submerged under volcanic ash, rocks and dust when Mount Vesuvius exploded in AD 79.

Archaeologists are still making discoveries there, including an uncommonly small house revealed last month with finely preserved frescoes of mythological scenes.