After visiting the Centre Pompidou, I walked around the area, and soon enough found myself in Les Halles, in the middle of the 1st arrondissement. I've actually been to this area before, in my previous visits to Paris, but somehow I didn't get the chance to pop my head into L’église Saint-Eustache.
L’église Saint-Eustache is a Gothic style church, built between 1532 and 1632. I did briefly enter this building a few years ago, but there was a mass going on, and therefore I postponed exploring it. This time, it was free, so I was free to meander inside.
As you can see, the exterior has plenty of Gothic elements to it. I wouldn't be surprised to see a gargoyle in this architectural environment.
The interior on the other hand, is very dark and gloomy. I must say that this isn't a welcoming place at all. I would be scared, to be honest. I wandered around, exploring its nooks and crannies, yet the overall feeling I had was of darkness. This is perhaps one building that I wouldn't want to be trapped at the end of the day.