November 15, 2025 - Limestone playground in Bleau.

Nobody goes to Bleau to climb on limestone and even less when it's in a dirty cave with only drop offs. When you're already there though and everything is wet with even more rain to come during the day but eager to climb outside, the limestone cave of Grotte de Seine-Port offers a fun alternative to staying home or climbing inside. Olaf joined me and it was our first time there. In a way, it reminded of when I still lived in Belgium and I would drive around the Belgian Ardennes, looking to climb anything or anywhere that resembled bouldering. Often in small caves or small patches of rock, all mostly limestone, a rock type that isn't very suitable for bouldering.
The already opened lines in Grotte de Seine-Port all have drop offs, meaning that you have starting point, follow an imaginary line up to a jug that is considered as the final hold and then you drop off. No topping out onto the rock.

We wanted to start warming up with the easiest published line, "Jour de Pluie", but besides a few pictures that didn't tell a lot about the line, no video, and only a vague description, it was difficult to determine where it exactly started, how it went and even harder to determine where it ended. Based on this, we climbed what seemed logical and close to the proposed grade, but afterwards found out that what we did was not exactly "Jour de Pluie". We started like "Lendemain de Grêle", followed that line up to an obvious big hold and then sort of came back a bit more to the right, to end at a jug. Soft 7A, and for the time I named it "Jour de Pluie (droite)". Not claiming any first ascent, because the line is so logical that it's hard to imagine that it hasn't been done before.

Fontainebleau - Grotte de Seine-Port - Jour de Pluie (droite) 7A(6C+)

"Lendemain de Grêle" does have a picture with a drawn line on bleau.info, so it wasn't very hard to follow what we could see on the picture. After I did it on my first attempt, Olaf followed in my footsteps.

Fontainebleau - Grotte de Seine-Port - Lendemain de Grêle 7A+

The most obvious line, and probably also the nicest one that we tried, was "Le Plafond de Nandy". After I tried some of the moves separately, I quickly found a sequence, but remembering it was difficult with holds that are hard to see on this type of rock. We barely put any tickmarks, because with so many white spots in the limestone, we could hardly make out the difference between a tickmark and a white spot on the limestone. Nevertheless, I was able to climb it on my first attempt from the start, albeit with a bit of improvising near the end as I had already forgotten the sequence. Very fun to climb that line.

Fontainebleau - Grotte de Seine-Port - Le Plafond de Nandy 7B

Finally, we think we found out how "Jour de Pluie" was supposed to go, but if this is indeed the line, it definitely didn't feel easier than "Lendemain de Grêle".

Fontainebleau - Grotte de Seine-Port - Jour de Pluie 7A(7A+)

Grotte de Seine-Port is not great for climbing, but it was definitely worth the visit on a rainy day like today. It wasn't raining yet when we arrived, but by the time we finished our session, it was pouring hard. All the time the whole cave stayed completely dry. So, when you happen to be in Bleau during a rainy period and you're still eager to climb outside, I can recommend it as a fun alternative. With so many possibilities that one can imagine, it's a nice little limestone playground. Olaf and I will surely go back one day during a rainy period.