Do you want some adventure? Did you know that there is an extensive network of caves under and around Budapest? So how about crawling through small holes, going down narrow paths and sliding down to come out in huge caverns every now and then, before disappearing through the next thin gap? If you answer with yes, then I would suggest to go caving in Budapest.
I did the Adventure Caving and it was a lot of fun. You get a jumpsuit and helmet with a lamp. Then you and your small group go through the caves for 2-3 hours. You should have a basic physical fitness, otherwise it will be quite exhausting and either you bring knee pads with you or you will feel your knees even the week after, because in some parts you will crawl on the stone floor. However, it is amazing, through which narrow holes you will fit. And do not worry, if you get stuck somewhere, after 3 days without food you just slip out again. Just kidding, there are different ways, so that certain bottlenecks can be bypassed, if there is a risk that someone would get stuck.
If someone is claustrophobic, it is definitely not recommended, otherwise you should definitely do it.
You can take your camera with you, but keep in mind that it is dusty and sometimes tight. The most suitable is probably a small ActionCam. At that time I did the caving I haven’t had my GoPro and took my Lumix on the tour. And although it is relatively small and handy, I had to ask others to hold my cam from time to time, because otherwise I would not have fit through the holes. But my Lumix was able to catch some nice memories for me in the low light.
Further information can be found here: https://caving.hu/