The Kossenblatt Castle Triathlon takes place in Kossenblatt, Brandenburg. The Spree River serves as the swim venue, with the grounds surrounding the local castle forming the event's core. Held in late summer, the race features off-road cycling, requiring a suitable mountain or gravel bike instead of a road bike. The event accommodates various participants: children compete in very short races, while newcomers and age-group athletes can join the Jedermann (everyman) events. Relay teams can divide the distances, and more competitive athletes have sprint or short-distance options.
The course begins with a swim in the Spree, followed by a varied bike route through natural terrain, and concludes with a run on the Schlosswiese before the historic castle. The sprint race includes 0.55 km swimming, 13.75 km cycling, and 4 km running. The short distance extends these to 1.25 km swimming, 26.75 km cycling, and 8 km running. Multisport LOS organizes the event, with Uwe Drendel as chief organizer and Christine Drendel also involved. Now in its ninth year, it is Brandenburg's only official cross-triathlon competition and includes state championship races for students and adults, which require a valid start pass.