Ecomarathon de Saïko

The Ecomarathon de Saïko takes place on 25 October 2026 in Toda, on the shores of Lake Sai in Saitama Prefecture, Japan, with an 11am start. It offers two looped formats, a half marathon and a 10 km, plus a 5 km parent-and-child race, on a peaceful course surrounded by lakes and ponds.

The event, which is also held in other Japanese prefectures, has an environmental and charitable focus, with donations to Second Harvest Japan, the country's first food bank. Although heavily urbanised, the Saitama area remains agricultural, with specialities such as Sayama tea and Chichibu udon. Hikawa Shrine in Omiya, one of the oldest in Japan, and Tokyo, just 20 minutes away, round out the sightseeing options.