Visited 3-times:

-as regular tourist spending few hours in Assisi only: it means running from parking lot close to S. Chiara towards the basilica S Francesco, being half an hour inside the basilica, having the rest for an hour to enjoy apperol spritz at Piazza del Comune Assisi, etc...

-as independent traveller accommodated close to Santa Maria degli Angeli for 3 days. It was sufficient to visit (almost) all important franciscan sites in/around Assisi: (1) Basilica di S Maria degli Angeli (huge 16th-century basilica with original church of Porziuncola inside - an important place in life and death of S Francesco), (2) City of Assisi with the Basilica of S Francesco (amazing church with three parts - described in detail by others), There are many important historical monuments within the city walls as described by others, I would emhasize the facade of cathedral S Rufino (important masterpiece of Umbrian romanesque style, interesting to compare with facade of Duomo in Spoleto), (3) S Damiano outside city walls (very quiet place, also important in life of S Francesco), (4) Eremo di Carceri (located in the area of Mt Subasio, it takes some effort to climb the mountain but one can feel Franciscan spirituality there), (5) Santuario di Rivotorto - I have not visited it, but it is not far from Santa Maria degli Angeli by public transport. It is another place where early franciscan comunity lived for certain time, before moving to Porziuncola.

Photo: upper parts of Monte Subasio not far from Eremo di Carceri, which is also part of WHS as well as quite large hilly area around Assisi. I did not take photos of sacred Franciscan sites from personal ethical reasons...

-as pilgrim walking from Santuario La Verna in Verna Mountains close to Bibbiena (Arezzo) to Assisi. This place has nice setting on steep hill with breathtaking views surrounded by beech forests. La Verna is another important place in life of S Francesco (stigmata). However, La Verna is not part of WHS despite its importance. There is a marked trail (yellow T - tau) from La Verna to Assisi, it takes ca. one week, and it is well-maintained, so, do not afraid to be lost even without pretty expensive official guidebook of Camino di San Francesco.

In conclusion, this site is very important in my life.