Cerro de Sirena (2404m) is the highest of the hills surrounding Guanajuato, in central Mexico.  For the FKT, start in front of Teatro Juarez, run to the cross at the top of "La Sirena" (about 3km, 480m gain), and return to your starting point. There are many possible variations.

Wild Basin is a huge drainage in Colorado's Rocky Mountain National Park. Hikes to the peaks at the head of the Basin always entail long approaches, usually 18+ miles round trip. It is aptly named: everything in Wild Basin is remote.

The "rules" for ridge traverses such as this are simple: You don't have to stay exactly on top of the ridge at all times, you just have to tag all named and significant summits along the way.  It seems logical to require that one close the loop, which requires roughly 30 miles of travel.