The International Four Day Marches Nijmegen () is the largest multiple day marching event in the world. It is organised every year in Nijmegen, Netherlands in mid-July as a means of promoting sport and exercise. Participants walk , or daily, depending on their age and gender and, on completion, receive a royally approved medal (Vierdaagsekruis). The participants are mostly civilians, but there are also a few thousand military participants. Military participants' distance is 40 km, in uniform, carrying at least marching weight for men aged 18–49; for women, the weight is optional. Summary The Vierdaagse (Dutch for "four days event") is an annual walk that has taken place since 1909. Based at Nijmegen since 1924, it now takes place in the third week of July. In 2016 it celebrated the 100th edition (reflecting that the marches were curtailed during the two world wars). Originally a military event with a few civilians, it now is a mainly civilian event. Numbers have risen in recent years, with over 40,000 taking part annually, including about 5,000 military, and is the world's largest walking event. Due to possible congestion on the route, since 2004 the organisers have limited the number of participants. Many take part every year, including several who have taken part in over 60 annual marches. The record is held by Bert van der Lans, who completed his seventy-first march in 2018, at the age of 86. Each day of the marches is named for the biggest town on the daily route. Tuesday is the day of Elst, Wednesday the day of Wijchen, Thursday the day of Groesbeek and Friday the day of Cuijk. The routes always remain the same unless there is a specific need to change. This happened in 2007 (route changed in 2006 but cancelled) when the walkers went along the Waalkade, beside the River Waal, on Wednesday for the first time due to congestion on the original route. The 2006 march was the first to be cancelled in 90 years (apart from 1940 due to World War II) when extreme heat during the first day's march caused thousands of drop-outs and two deaths. Following the 2006 cancellation, it was decided that the organising committee would adjust the start time/distance/finish time to manage the event, instead of outright cancellation. The 2016 centenary event responded to unusually hot conditions by adjusting starting times and/or increasing the valid finishing time to