Koto City and Chuo City in southern Tokyo. were the location of the Olympic Village and many other Olympic venues. There are a couple of nice running routes here. See also this super-cool map which overlays GR routes and Olympic venues!
Chuo City: Olympic Village Route. Nearly 11 km, flat. This route, primarily in Chuo City, passes by the Olympic Village, and runs along mainly waterfront paths to Toyosu Gururi Park, then passing the Gymnastics Center, BMX Course, and Tennis Center. Access: Kachidoki Station.
- Longer run: combine with Odaiba Island route.
Koto City Route. Up to 13.3 km. Just east of our Olympic Village route, starting at Tatsumi Station. Nearly all off road on bike/waterfront paths. Starts at Tatsuminomori Seaside Park, passing the Aquatics Center and then Yumenoshima Park, location of the Archery Field. For a run of ~13k, extend for 1.5 km on a path along the Arakawa River, through Shinkibaryokudo Park. This is the location of the canoe/kayak events from the 2020 Olympics.