TL;DR: Multi-pitch climbing took more time than planned, night fell, we didn't have any head torches to hike back down and through a swamp region and cross a river.
Time is around 2005, location is Agulhas Negras Peak, Itatiaia National Park, between the states of São Paulo and Rio in Brasil. My climbing experience: 1st year climbing, had done only 1 or 2 short multi-pitch climbs in easy accessible terrain. Partner: complete beginner, zero multi-pitch experience.
This climb has a somewhat long approach, but not difficult in day light. From the parking lot you cross a small bridge over a river, then follow a path snaking around a large flat swamp area, around 30-40 minutes, then you hit the slopes of the mountain. You keep hiking and scrambling steep rock for another hours or so before you gear up for climbing.
Climbing went well, I've led all the route, we took our time at the summit. Decent was rapelling, which also went well. Then we started decending the scrambling part of the path in steep rock. We had an amazing view, the rock peaks around us turn bright red before the sun set. We did sit to appreciate the view, oblivious of the fact that we soon would have no more light, and we had forgotten our headtorches on the car. At low latitudes, sun sets fast and in 5min it's pitch black.
We started hiking back the swamp area in the last light, starting to notice that we were basically screwed. When it got really dark, we sort of had to feel the path under our feet, as opposed to stepping onto vegetation or wet terrain from the swamp patches that were all around us. At some point I feel and half of my body ended up under water, I was drenched. Last night the temperatures went below freezing, so I got worried of overnighting wet could end up bad. We did not have any extra clothes, extra food, nothing, so we just continued trying to make our way following an instinctive direction towards the river.
At some point we did reach the river, but not at the bridge, and we had no idea if we were up- or down-stream of the bridge. The terrain along the river was slippery and difficult to walk, particularly in the dark. The river itself was furious. If it was only the cold we could try to cross it, but it was full of boulders and very strong stream, too risky to cross it with daylight. In the night, just forget it.
We discussed if we should split, each one go one way to try and find the bridge, but how would we find ourselves later? The noise of the river made it difficult to yell to communitate at distance.
Due to extreme luck, we suddently saw light in a cabin on the other side of the river. Worth mentioning that this is the only cabin allowed in this entire park, and is closed almost all the time. But this day one mountaneering club from São Paulo was having a gathering there. Only problem was that the cabin was on the other side of the river. So we tried to get as close as possible to the cabin and waited until someone got outside, so we started yelling for help.
It was amazing to see that person running inside the cabin and 30 seconds later at least a dozen people wearing head torches poor out of the cabin and run to the bridge, which was 50-100m close by. In a couple of minutes they got to us, with a couple of spare head torches for our way back.
The lesson was obvious: after that day my head torch became a fix part of the bottom of my backpack, with an extra set of batteries just to make sure.
I do sometimes go for climbs without the head torch, but in very particular situations for example climbing in Norway in July, were basically there's no night :)
TL;DR: multi day mountain climbing with not enough warm clothes, miserable night shivering.
Around 2007, in the mountains close to Rio, in Serra dos Órgãos National Park, we went for a 2 days climbing. Basically on the first day we climb a face called Paredão Paraguaio, on Morro da Cruz, muit-pitch trad, overnight at that summit, and next day hike to Agulha do Diabo for another climb.
The logistic problem is that we had to climb on the first day with all the gear to overnight plus food and some water.
Also, this was February, late summer. Mountaneering season in Rio is winter, since summer is too hot to climb. I lived in Rio, it was like 38 C when I was packing for the trip. It's strange to say but it feel strange to pack warm backpacks and woolen lines when you're sweating in t-shirt and shorts at home :) So, I didn't take enough clothes. In fact, all I took was the t-shirt and shorts I was wearing, and a very thin wind breaker jacket. We had a 2 men tent. My climbing parter was more prepared, she took fleece trousers and jumper and a hat.
During the approach and climb it was hot, t-shirt and shorts was the right thing to wear. But as the night feel the temperatures dropped.
That night was around 10 C at the overnight place. Not too cold, except if you're in T-shirt and shorts. I didn't sleep a second all night. Lying on the ropes, backpacks and other gear helped a bit to isolate the cold from the ground, and spooning with the climbing partners also helped in keeping at least one side of my body sort of not too cold. But it was a miserable night.
Next day we headed to Agulha do Diabo, done the climb and hiked back to the car.
Lesson: don't underestimate the cold. Take one extra layer. In this case should have brought a small inflatable matt.
LR;DR: night fell while rope soloing a long route.
In the east face of Pão de Acúcar, in the middle of Rio, there a route called Iemanjá. It's 8 picthes of Brasilizan 6 grade climbing, all boltet, with some famous run outs. It's slab climbing with lots of tripocal vegetation on the well, beautiful bromelias everywhere, and giant cactii next the top. It's amazing how these plants grow on the rock in steep terrain, their roots just attached to the rock like lizard's feet.
I was practicing lead-rope soloing at that time. My experience was rope soloing short and easy routes, 1 or 2 pitches. But this day I had a terrible idea: rope solo Iemanja, a route that was higher grade and much longer than what I had done before, and to make thing worse, I decided that on a whim about 10:00 in the morning. Got my gear, onto the bus, hike to the east face, started climbing around noon. It gets dark around 18:00-18:30 in Rio at that time of the year, so I had 6 hours to finish the climb. Pão de Acúcar has a cable car which is free for climber to decend, so that makes the logistics and planning easier.
Rope soloing is time consuming. I was using rudimentary method with minimal gear, using an ATC rope break with a prussik backup, and prussiks on the rope to climb back up.
A couple of picthes before the summit the night fell. As always in Rio, night falls quite quickly. 5 minutes after sun set it's pitch black. I did have a head torch with me, however the main problem was to find the next bolt. Climbing routes in Rio are famous to have long distance between bolts. Particularly in easy pitches of higher grade routes. These last 2 pitches I had to climb in the dark were easier, grade 5 and 4, since the face steepness drops near the top, so those pitches didn't have many bolts and the fear that I have overseen one bolt was getting the best of me.
At some point I remember that I accidentally stepped on a bromelia, these plants are full of water, and that water dropped and made the rock and my feet all wet, my climbing shoes lost grip and on a whim I hugged a giant cactus which was next to me, closing my eyes expecting to be pierces by the spikes (which in that scenario felt much better than a fall after a run out), and luckly these giant cactii have spikes on the upper part of their trunks, but none at the bottom, so I was happy when I noticed that I was not pierced.
I got to the summit around 21h. Ie, 2.5h to 3h climbing these 2 pitches in the dark. Such a strange sensation, you change from an epic in a dark and solitary mountain environment, then you cross a fence and fall right in the middle of an open air shopping senter full of tourists taking silly pictures looking at you wondering where the hell you came from and why you look like shit. Cable car back down, bus, home before 22h. "How was your day?", ask my non-climber room mate... "Ok, it was ok..."
TL;DR: lead fall onto a leadge on the 4th pitch of a remote route. Broken heel. No rescue available. Between crawling the trail and hitch hiking, took me 20h to get to the hospital.
The Five Peaks, Cinco Pontões, Foca (Seal) Peak normal route, is a unique formation ... TBC
TL;DR: night feel during a long mountain climb, got lost in the route, rain; Near miss during rappel due to not having the knots on the ends of the rope.
In one of the best climbing destinations in Brasil, Three Peaks State Park, we went for a classic climb there, a route called CERJ on a face of Capacete. CERJ route is a classic: 400m long, mix protection, traverses, aid climbing near the top. Capacete has a vary large and flat summit, and finding the rappel route is not always straightforward, but highly recommended, as one can come back to the ground after only 4 off 50m rappels, as opposed to rapelling the 400m long climbing face not always prepared for rapelling.
The day started a bit sad, cloudy and unstable, we started to forget about our climbing plans that day and took a slow breakfast at the cabin, 1h walk from the start of the routes. However at around 10:00 in the morning the skyes cleared and the day turned out to be a nice sunny winter day. We got our gear and headed to the mountain without a second thought. "Just make sure you get your head torch". We were a team of 3. Packing, hiking, finding the start of the route, etc, we started climbing around 12:00. Sun set is around 18:30, so a bit over 6 hours to climb 400m, find the rappel route and decend. It's normal to rappel in the dark in this region, as climbing season is in winter and days are short. But it's highly recommended to start rappeling in the last light, as finding the top anchors is difficult.
The climb went well, but it got dark 2 pitches before the summit. What was in front of us was basically one 20-30m easy aid climbing pitch, with a long sequence of old screws/pitons, which is time consuming for 3 persons to climb, then a 70-80m easy pitch to the top. This last pitch gets easier as the terrain gets less steep, but there's long distance between bolts and not much trad protection available. After ther aid climbing, it was pitch black. With the head toch on, I started leading this last pitch. Due to the length, we all knew that we had to climb simultaneously at some point. Due to the darkness and the long distance between pitches, I got lost on the rock and didn't find any bolts. I remember placing a marginal stopper at some point and climbing almost a full rope length without any other intermediate protection. Then it started to drizzle, and the drizzle quickly turned into rain. At some point I gave up looking for bolts and continue to the top before the water would start pooring down the rock. This rock has good grip when wet, however it's not easy to convince your brain of that fact :) Finally I found the top anchors at the end of the route, 2 sturdy bolts, made the anchors and belayed the other two.
Despite the rain, it was foggy. So it was difficult to find the marks to the rappel anchors. With patience and a few wandering around we finally found it. We started rapelling. Four 50m vertical rappels. The main concern is to find the next anchors with a head torch, not always easy. So you're constantly worried to rappel past it and having to climb back up the rope. I don't remember if it was the first or second rappel when that happened, I rappeled pass the anchor and didn't see it. I was sure I was still above the bolts and rapelling down the rope when I suddently look down to look for the anchors and realised that there was about a meter or two of rope hanging below me, without the knots at the end. That cold shivering feeling running up my spine and the reflex of grabing the rope as hard as I could with one hand while I look for the prussik loops from my harness with the other hand to prepare to climb back up the rope and find the anchors.
There was in my understanding a conflicting culture at the community of climbers at that place at that time, that tended to weigh the risks of having and not having the knots at the end of the rope. It's typical in this region to have many long rappels, like 10+ off 50m rappels, constantly with time constraints due to short winter days. There was those who defended not having the knots, due to time it takes to make and undo them, and the risk of starting pulling the rope with the knots on. The consequence being of course you'd get stuck, have to lead climb again to pull the rope, which is time consuming if possible at all. So I sort of understand the optimistic way to see it: just pay attention at the end of the rope and you'll be fine. On the other hand, there was those who defended always having the knots at the end of the rope, because the risk is... well, you can die.
I think I did my fair share of rappels without the knots, and without backup prussik at that. That created almost a paranoia in my head of constantly checking everything 3x when rapelling, which is good. But that near miss and the memory of that shivering feeling up the spine made me reconsider and always have the knots and the backup when rapelling. It just feels stupid not to.