What is bouldering?

What is bouldering?


In recent years climbing has become a mainstream sport. Bouldering is the fastest growing form of climbing. It’s easy to start bouldering, and highly addictive once you’re hooked. It’s a sport with a laidback and social character. There’s no fuss with climbing ropes and you only need sporty clothes and clean, indoor sports shoes or (rented) climbing shoes to start. The climbing walls are 4m high and there are thick falling mattresses underneath.


Bouldering improves your general fitness. Train your strength, endurance, flexibility, coordination and agility in our gym. This makes it a great way to spend time with friends whilst working on your physique! Let the worries of your busy day fade away as you focus on the ever increasingly complicated routes Radium Boulders offers.

Start to boulder


Haven’t been bouldering before? Come over and try it! There are plenty of easy and challenges routes for you to try. We have 10 coloured circuits with 16 – 18 boulders each, one of which aimed specifically at children. Every week we replace some routes to keep it interesting. In every circuit there are routes with various movements and degrees of overhang. This provides you with a full workout!


Keen to try it, but prefer a group setting? Join our monthly Fundamentals of Bouldering class for beginners. Find the next one here.


What we offer


Radium Boulders offers a large indoor bouldering facility (1700m2 floor space en 700m2 climbing wall) with extensive training opportunities. There’s a crossfit setup, 25° and 40° LED MoonBoard and campus board. Done with the workout? We have a cosy bar with great coffee, appetizing food and a wide range of beers and soft drinks.


As a Radium member you can also boulder at our sister gyms!

Energiehaven Utrecht | Kunststof Leiden | Roest Zwolle


Corona regulations

  • Access by reservation only, so reserve your slot.
    Be on time, as we cannot let you in before or after. You cannot stay longer than the reserved time; please keep an eye on the time. This way we can ensure everyone gets a chance to boulder. Reserve via the Toplogger app or the Toplogger website. You cannot make reservations via phone or email. Groups can make their reservations via the groups & parties page.
  • Wash your hands regularly during bouldering, at least when you come in and when you leave.
  • Keep at least 1,5 m distance from other climbers and our staff and follow directions from our staff.
  • Avoid physical contact with other climbers. Don’t shake hands or give hugs. Don’t touch your face during the bouldering session; wash your hands first.
  • Spectators are not allowed, boulderers only! Parents of kids aged 8-11, join your kids rather than accompanying them.
  • The changing rooms and showers are closed, so change at home.
  • Use your own/rented materials, don’t share chalk with each other.
  • Follow the recommendations from the health authorities in relation to minimising the spread of Covid-19.
  • Stay home if you have virus related symptoms. Stay home if you have one of the following symptoms: cold, runny nose, sneezing, sore throat, light cough, raised temperature or fever.
  • Stay home if someone in your household has a fever of shortness of breath. Keep it safe for everyone, so you don’t accidentally infect someone.

Safe bouldering guidelines

  • Don’t sit, stand or walk on the mats.
  • Keep 1.5m distance from other climbers.
  • Don’t wear jewelry or watches during bouldering.
  • Put your chalkbags, brushes and other items besides the mats.
  • Ensure there’s a safe landing zone for other climbers.
  • Climb down rather than jump out; we have added downclimbing holds to make this easy.
  • Divide the impact, land on both feet.
  • Keep your arms in front of or besides your body; do not land on them.
  • Always bend you arms and legs during the jump.
  • Cushion yourself by bending your knees during the impact.
  • Roll backwards to further cushion the impact when falling from height.
  • Never roll forwards.
  • Practice falling regularly and make sure you’re in control.
  • Ask advice if needed.