In addition to over sixty thermal springs, Budapest is also a city of caves. In the limestone under Budapest, the heated water that feeds the spas has formed a huge cave system, thought to extend more than 100km. The longest is the 19km Pálvölgyi Stalactite system located in the Duna-Ipoly National Park, about 30 minutes drive away. It is a real multi-level labyrinth with most of its chambers under the residential districts of Budapest. If you are looking for a unique experience, pre-book a two-three hour cave tour (you will be provided with overalls, helmets and headlights). Guided by experts, the expedition will see you scrambling up cave walls, crawling through narrow paths and exploring caverns no one else you know will have ever seen – seriously crazy and wet.
Back out in the open, it's time to experience Budapest's thriving extreme sports scene. There is also Budaring Go-karting or Eurocentre Go-karting closer to Budapest. For a bit of off-road mountain biking, head for the Buda hills above Moszkva tér – if your legs are not up to the long uphill slog, the Cogwheel Railway offers an easy alternative. Get rid of the hungaroring stuff
You should also try the 'Fun Extreme Canopy' in Visegrád, to the north of Budapest. This is a massive zip-wire system between ten poles over 900 meters in length. Once kitted out, you climb up Pillar One (which is 14m high) accompanied by two escorts. At the platform on top of the pillar, the escorts fasten the pulleys to your belt and you slide downhill from pillar to pillar – easy … except you are flying over treetops and ravines at about 50 km / h! After getting off the last pillar, walk back to the start along the forest path for a beer (and a chaser of something stronger) at the Nagyvillám Hunters Inn. Or if you prefer water to air, try wakeboarding and water-skiing on the Danube.
Of course, booking all this and not speaking the language is a challenge and, not having been before, you need to know the best places to eat, drink and make merry in the evenings for your stag weekend in Budapest. The solution is to speak to an established and reputable company that will organize the whole thing for you. You can choose your own bespoke package and they do the rest – the whole thing – from when you land to when you take-off, bleary-eyed and a bit smelly … you simply need to gather your mates, book your cheap flights and pack. Remember to look for a company that will do your airport transfers into the city, will find you competitively priced hotel accommodation and will book you the best choice of high-adrenaline activities.