This is a nice waterfront run in Chiba combining two parks: Inagi Seaside Park and Makuhari Seaside Park. It’s up to 6.5 km one-way, with good add-options. You can choose to run on seaside paths or interior park paths.

Start in Inagi Seaside Park. You can run along a nice seaside path, or on interior park paths. There’s also a wide beach — the sand is soft but might be OK near the water, situationally. It’s ~2.7 km through the park. Continue on a path along the water for ~1.5 km, and then cross the Hanami River into Makuhari Seaside Park. Here, we choose the interior path, but there’s also a seaside option. The path ends at a large field just past the Marine Stadium.

Add-Ons: Additional paths in the parks. There are also paths along the Hanami River, and along the Hamada River (in Makuhari  Seaside Park).