What remains of Paris’s mysterious underground ice houses?

There once existed immense underground ice houses beneath Paris.
What remains today?

Long before the refrigerator, the capital stored its ice in a secret network of wells and underground warehouses.

As early as the reign of Henry III, people cooled their drinks with snow, but only the privileged had access to it.
In 1668, the first ice cafés made ice popular, and the word “glacière” appeared as early as 1680.

The hamlet of La Glacière, near the Bièvre river, harvested ice in its ponds during winter.
Stored in quarries in Montsouris, it was unearthed in summer, perfectly preserved.

A simple system, yet incredibly effective.