Bouldering is a style of rock climbing undertaken without a rope. The climbs or "problems" are typically short enough such that a fall will not result in serious injury. The focus of bouldering is typically on power and strength rather than endurance (Bouldering is to climbing what sprinting is to running). Bouldering usually takes place on large boulders, hence the name, but often people will practice bouldering at the base of larger rock faces or on artificial structures (blue stone bridges being a particular favorite).
The Lactic Factory
On Monday evenings, most weeks you can find some LUMC people down at The Lactic Factory, a dedicated bouldering-only climbing gym. It is located in Abbotsford and is easily accessible via public transport. The bouldering at The Lactic Factory is quite tough so it is usually recommended that you get to a regular climbing gym before you go to Lactic. A visit will set you back $13.