Covered sewers were introduced during the reign of Napoléon Bonaparte , and today's network of more than 2,100 km (1,312 miles) of sewer tunnels was begun in 1850.

Covered sewers were introduced during the reign of Napoléon Bonaparte , and today's network of more than 2,100 km (1,312 miles) of sewer tunnels was begun in 1850.

Covered sewers were introduced during the reign of Napoléon Bonaparte , and today's network of more than 2,100 km (1,312 miles) of sewer tunnels was begun in 1850.

Categories: 100 km (1, 312 miles) of sewer tunnels was begun in 1850., and today's network of more than 2, Covered sewers were introduced during the reign of Napoléon Bonaparte