Tenth Zone East (イースト テン サイド; East Ten Side). The first city was chosen as the production center of small ships and passenger cruisers. The pollution problems are due to the cosmic-scale industrial development of the zone, located on the 10th block of the enormous complex, hence the name of the area. The polluted sky can hide the sun even for an entire year, so prepare your gas mask to race in this smoggy world.
Tenth Zone East is similar to Lightning because both have pollution problems.