ATW Hertfordshire & Middlesex Triathlon

About this event

Set in a 100-acre nature reserve near Rickmansworth, this triathlon offers something genuinely special: a swim in a Hertfordshire lake that's normally closed to the public. The course takes full advantage of the setting, with a surprisingly rural bike route through Middlesex countryside followed by a run along peaceful nature trails winding through the reserve. The venue itself is worth the entry — serene lakes, abundant wildlife, and woodland trails create a backdrop that feels miles from anywhere. Multiple formats are available, from SuperSprint to Standard distance, plus Aquabike and relay options for those racing with friends. It's a chance to race somewhere most people never get to swim.