[Source](https://scp-wiki.wikidot.com/scp-176)
Special Containment Procedures: SCP-176 is contained on-site under the cover of industrial chemical contamination. Any civilians attempting to enter SCP-176 must be detained.
Multiple high-speed cameras are set up within the observation room and linked to continuously running analysis computers. If any deviation is observed in the recorded sequence, all recorded data must be immediately backed up and senior staff notified. source
SCP-176 is a factory with three entrances (a triple docking entrance, a personnel entrance, and an entrance to the observation room via a staircase outside of SCP-176) and two rooms (the factory floor and the observation room, separated by one-way mirrors).
The interesting part is that when someone enters the factory from the docking or personnel entrances, nothing happens it's just an empty room. It is impossible to access the observation room from inside the factory. However, if you manage to enter the observation room via the exterior staircase, you will witness the anomaly of the SCP. From the control view, you’ll see a modified reality: the factory floor is no longer empty. It is now filled with about 50 square meters of machinery, and five people in clean white suits are working the machines. After 5.9 seconds, four individuals in black combat suits without any distinguishable markings or identifiable gear, force their way in through the employee entrance and open fire on the workers. After 11.3 seconds, the machine in the room emits a flash of light and radiation (some kind of explosion), and the scene resets. It then repeats itself infinitely. This sequence has been observed hundreds of times, with no variations in the events.
The Foundation has tried to intervene in the event but without success. You can’t break the walls, doors, or windows—they feel much more solid than they should. Any damage done before the start of the event instantly repairs itself when the loop resets.
To this day, the Foundation is still trying to understand the nature of this anomaly.
A lot of fun to make these posts, bring me back to scrapping the Wikipedia and some youtube videos to gather some info but on the smaller/less famous SCP there is less content available sadly.