The porte de Quirieu is on the site of Cremieu's oldest gate. The current structure was build in 1535 and restored in 1930. The gate stands at the end of the road that leads to Chateau Delphinal.
In my picture, notice the drain to channel ground water out of the old city.
The village's page (translated by Google) shows the red limestone on the face and says that is the result of the burning of an adjacent house.