We have visited three of these:
Notre Dame le Grande is in the middle of town, opposite the Palais de Justice. The present church owes a lot to Eleanor of Aquitaine in the 11th century, but there are records of an earlier church on the same site. The interior of the church is highly decorated with frescoes and memorials.
This memorial really interested Susan. Such a fashionable group of people!There is another picture of this church here.
The cathedral in Poitiers was also started under the orders of Eleanor of Aquitaine. It has 13th century carved wooden choir stalls, some important stained glass, and a late 18th century organ.
This church incorporates the 6th century tomb of St Radegonde, the founder of the first convent in France. This is another highly decorated church, with frescoes and ancient stained glass.
There are other places of interest in Poitiers, including the baptistry and a rather good looking (if not terribly attractive) market.
We will be exploring further, so no doubt there will be more photos