Where The Bourne Identity was Shot
The church in front of which Matt Damon is standing with Franka Potente (implied to be not very far from their hotel in Belleville), when he begins to assemble the evidence for his lost identity, is St Joseph in the 11th arrondissement.
To see this church, simply proceed as follows: At the start of Walk no. 10, on leaving the Metro station Belleville, walk into Rue du Faubourg du Temple, full of the most interesting shops that sell all kinds of third-world tat from (probably toxic) Chinese Barbie dolls and fake fur jackets to flesh-coloured Christs that glow in the dark.
Turn left into Rue Saint Maur and walk once around St Joseph’s Church on your right before continuing into Rue de l’Orillon. (If you walked once around the church, this street is now on the right hand side of Rue Saint Maur.) After a hundred meters or so, turn left into Rue Louis Bonnet where you can see the Hotel de la Paix from The Bourne Identity, still closed after what must have been a massive fire. (Quite frankly, it does not ok as if the hotel was to reopen any time soon. The second floor has been bricked up to prevent squatters from getting in.)
From here on, simply continue as advised in the book. (You may also want to note the large number of really good, really cheap – if, admittedly, not exactly pretty – Chinese restaurants in the street.)