Over time, the gate had rusted and even the stone ramp that came all the way to the basement was weathered. Since the building was in bad condition for a long time, the basement had been all but abandoned.
Had it not been for the fact that the entire building was made from stone and bricks, the water leaking in from the walls would have probably rotted any wood that may have been used back then, leading to the collapse of the entire building.
Lucius had to thank the great grandfather for having the smarts to think for the future and not using something like wood for foundation and flooring. This had now allowed him to have an almost perfect place to do his experiments.
The secondary entrance to the basement is what Lucius will be using to leave the place secretly and also to transport any… 'out of commission' subjects and broken samples. Plus other valuable things he did not want too many people to see.