Europe has many megacities, whether in London, Berlin or Athens, each with a very large group, and appears to be growing every year. However, the old continent has one capital, which is not only the largest, but also the most popular officially.
It boasts the title of Europe's most visited city in Paris, France. AXA figures show that it welcomes more than 30 million tourists a year than any other city in Europe. People flock there to see famous landmarks such as the Eiffel Tower, the Louvre and Notre Dame Cathedral.
Paris is also huge. According to macro trends, the current Metro population in 2025 is 11.3 million.
But despite all the beauty of the earth, there is something terrifying under the city.
Deep inside the street there is a cold maze known as the catacombs. This is a network of tunnels that holds ruins of around 6 to 7 million people.
Many tourists often miss it, but it is one of the most memorable parts of the French capital.
The underground passages were originally limestone quarries, but by the late 1700s, Paris was facing a serious crisis.
The cemetery was overflowing with the smell of the body breaking down affecting nearby homes and businesses.
According to the official Catacombs website, the largest cemetery, Saints Innocents, has been in use for nearly a thousand years.
So the authorities made the bold decision to move to the quarry of Tom Aisia, where their bones were abandoned.
From 1785, workers moved remained in the tunnels at night to avoid upsetting the public.
This process took decades during the redevelopment of the city under Napoleon III in the 1850s, particularly after the French Revolution.
Nevertheless, the tunnel was officially consecrated in 1786 and was named the Paris Municipal Study.
However, they soon became known as the Catacombs in connection with a similar burial chamber in Rome.
The complete tunnel system extends below most of Paris (about 800 hectares), but only small sections that are publicly available are available.
Inside, the skulls and bones are stacked neatly along the wall, and the plaque has a message about the vulnerability of life, death, and existence.
The tour was appointed in the early 1800s and officially opened to the public in 1809.
Today, about 550,000 people visit the catacombs each year, passing through one Avenue Du Colonel Henri Lortugai.
The tunnel is closely monitored and only the specified routes are accessible.
Part of the network is falling apart over time, and maintaining the site is a continuous challenge due to humidity and decay.
