In the past weeks, the government has been planning for a possible mass evacuation of tens of thousands of people who live around the vast volcanic area known as the Campi Flegrei, or Phlegraean Fields, from the ancient Greek word for burning.
Sulphurous fumes escape from the surface, giving the area a surreal look and making it a magnet for tourists.
Residents have become used to the smell, the fumes and the trembling.
There were more than a thousand quakes in September, most of them minor.
But a 4.2 magnitude earthquake on September 27 - the strongest jolt in more than 40 years to rattle the volcanic field - sparked fears that what scientists call a "seismic crisis" might be under way for the first time since the early 1980s.
Recent seismic activity has heightened concern among people living in the volcanic area of Pozzuoli.
The big quake, which caused no serious structural damage, and about 500 smaller ones so far in October have made residents such as Annamaria Scardi, a mother of two teenagers, feel tense.
"Even those small ones (quakes) make us afraid," she said.
"We are worried because (we are supposed to) run away but where do we go? Where?
"This is the situation.
"We're on edge."
Experts say there is no imminent threat of an eruption but they are concerned that the geophysical activity is causing ground uplift and descent, which can destabilise buildings.
The government, which discussed the situation in cabinet this month, would order an evacuation if civil protection officials warned buildings were in danger of collapse.
Known as bradyseism, the shifts are caused by the filling or emptying of magma chambers deep underground.
When a similar crisis struck four decades ago, it lasted several years and forced the temporary evacuation of 40,000 people from Pozzuoli, known as the hometown of actress Sophia Loren.
"My family is divided ... I want to stay, but my wife and children are looking for a house in the Castel Volturno area," said Vincenzo Russo, referring to a town about 30km north.
"When you sleep at night, the nightmare is always there.
"You forget the situation and you're on the couch, and then the tremor is there with you.
"There are big ones and small ones.
"Yesterday, for example, we had two small tremors before lunch," he said.
On a recent afternoon, Angelo Prezzini and friends, gathered in the courtyard of a social club for retirees to play cards as they do almost every day, took a more sanguine view.
Prezzini, 78, said he would defy any evacuation order, while 66-year-old Luigi Ilardi, chimed in "we are used to it".
"I've been used to it since I was 13," Ilardi said.
