Butte-aux-Cailles

Neighborhood · Butte-aux-Cailles (13th)Paris,France

A Paris hill left at two storeys because the quarried ground beneath would carry nothing higher, with a hot spring feeding its fountain and pool.

The Butte-aux-Cailles is a hill too hollow to build on. Limestone was dug out from under it for centuries, and when the city rebuilt itself in stone in the nineteenth century the engineers found that the ground here would not carry the weight. Six-storey apartment blocks went up all around the hill, but not on it. What stands on the hill is what was already there: two-storey houses, small workshops, and lanes with kerbs and cobbles, in the middle of a district of towers and boulevards. The other thing under the hill is hot water. A borehole sunk here in the nineteenth century went down five hundred and eighty-two metres before it reached water, and that water comes out of the fountain on the square at about twenty-eight degrees. It is drinkable and free, and people queue with bottles. The same water fills the swimming pool next to the fountain, a brick building of 1924 with an indoor basin under a curved roof and open-air basins beside it. The hill is named after a man called Caille who bought the land in the sixteenth century, and not after any bird.

Worth knowing

Good to know

The part worth walking to is the edge of the hill — The old quarter is only a few streets across, so head out to the line where the low houses stop and the tower blocks begin.
Evenings fill the main street — The bars along it draw people from the whole south of the city at the weekend, and the lanes behind stay quiet even then.
The open-air basins run in the warm half of the year — The indoor basin works all year under its curved brick roof, but this is a municipal pool and it closes for maintenance without much warning.
Come to walk, not to see a monument — There is nothing here to queue for and nothing to buy a ticket for. What you came for is the difference between one street and the next.

Things to do

1
Fill a bottle at the fountain, then swim in the same water
The fountain stands on the square in front of the swimming pool. Put your hand under it: the water is warm, because it comes up from deep underground rather than from the mains, at about twenty-eight degrees. It runs day and night, and there is often a short queue of local people filling five-litre containers. The pool beside it draws on the same borehole, with an indoor basin under a curved brick roof and open-air basins beside it in the warm months.
2
Walk downhill until the buildings get tall again
Start on the main street and take any turning that drops away. The houses stay two and three storeys, with gardens behind them, until you cross an invisible line and the six-storey blocks begin. Find that line. It runs roughly along the edge of the old quarry workings, where the ground became solid enough to carry a heavy stone building.
3
Look at the painted walls twice, low then high
The lanes here have been painted on for years, and none of the work was commissioned. Shutters, gable ends, doorways and electrical boxes all carry paintings. Walk one street twice, once looking at street level and once looking above the first floor, and you will find two different sets of work.