In around 1205 St Francis chose these caves above Assisi as his hermitage where he could retire to contemplate spiritual matters and be at one with nature. The carceri (isolated places, or 'prisons') along Monte Subasio's forested slopes are as peaceful today as in St Francis' time, even though they're now surrounded by various religious buildings. It's a claustrophobic walk down to Francesco's Grotta (cave), where he prayed and slept on a stone bed in his later years.
Take a contemplative walk or picnic under the oaks. Don't miss the series of bronze statues along path through the woods of St. Francis (kicking back on the ground, sandals off) and two friars, Ginepro and Leone, staring at the constellations. It's a 4km drive (or walk) east of Assisi, and a dozen nearby hiking trails are well signposted.