The 88 Sacred Temples Pilgrimage
1400km pilgrimage clockwise around Shikoku
While the traditional way to do this is to allow 40-60 days and walk in the footsteps of the great saint Kōbō Daishi in your personal search for enlightenment, these days, most pilgrims (henro) make the journey on a bicycle, or in a car or bus. Allow 10 days by car, or 15-20 days if on a bicycle.
The good people of Shikoku have been hosting 88-temple pilgrims for 1200 years, so everything is well set up. The route is clockwise and circular around Shikoku - and henro should journey from Temple 1 to Temple 88, then back to #1 to complete the circle - for a circle is like the search for enlightenment, never-ending.
Do plenty of homework before taking this on - for those with the time and the inclination, this will be your most rewarding experience in Japan.