Then after everyone's gone, stay on to see the marvelous 13th-century sculpted Angel's Pillar (Pilier des Anges) in peace.
There is always a large crowd of people waiting to see the Angel's Pillar. 
mnli hypothesis: There is always a large crowd of people waiting to see the Angel's Pillar.  premise: Then after everyone's gone, stay on to see the marvelous 13th-century sculpted Angel's Pillar (Pilier des Anges) in peace.