Scary holiday house shenanigans

The year was 2016, I believe, and it was September. My family - my parents, our family dog, and I - went to France for a vacation. My mother had booked a holiday home near the French city of Obernai that looked nice in the photos. When we arrived, the landlady greeted us, though communication was difficult since she spoke little English or French while my parents and I, just 12 years old at the time, knew even less. I remember how she seemed nervous explaining that we must activate the alarm system each night and lock the doors to the lounge/winter garden with a large metal shutter that reminded me of blast doors.

What struck us as odd was that we weren't shown the entire house. My curious dad and I decided to explore further and found some strange things. There were two upstairs bedrooms and one on the ground level. The downstairs bedroom was normal except for a window that didn't close properly, but the upstairs rooms were peculiar. One had 5 or 6 beds, none facing each other - we assumed the beds were just arranged oddly. The other had a very large bed and a second, locked door to the left. A similar locked door was across the upstairs hallway near the bathroom, supposedly leading to a small balcony and another inaccessible door.

The creepiest part was the basement. The landlady didn't show it to us, but the key fit, so my dad and I went down to look around. A stairway led to an L- or Z-shaped basement. At first it seemed normal, but the end was concerning - the last part was tiled and had an amateur mosaic of a red-haired woman on the wall. My dad claimed there were meat hooks too.

For some reason we stayed the whole week, and odd things happened. We all felt uneasy after dark, understandable in such an eerie house. I'm 80% sure I heard creaking from behind that locked upstairs door. I also felt watched and depressed, unusual on vacation, though maybe just my tendency toward paranoia.

Most disturbingly, our normally chill Labrador had what seemed a panic attack one night, howling and terrified for hours, highly abnormal behavior for him.

We were relieved to leave after that week. I still dream about the house and shiver remembering it. If anyone has information to help locate it, please let me know. My parents don't recall the exact address, and I was too young. I can recreate the floorplan and mosaic if it helps.

Anyway, I hope you enjoyed my story. Have a nice day!