don't do that!

There are statues of saints in the niches at the bottom of the buttresses. On the left side, a niche remained empty because you can not see inside the ground. This is optimization!

The empty tower at the back on the right helps to support the main church structure.

The inside of the Chiuse of Bauma Negra, completly empty.

The Hotel-Dieu in Lyon is a former hospital now completely empty but the roofs are a wonderful playground This was the first hospital in Lyon, built by the brothers Pontiffs in 1184.

This corridor is almost completely around one of the last level gave me the solution to the legend that surrounds the courthouse in Brussels. Indeed, the legend says there are so many rooms that nobody really knows the number. It would suffice to count them you say? Certainly, but the legend also says that some rooms are hidden! And it's true! This corridor will lead to narrowing to a dead end. But shortly before, once a straight line (since it is the turn of the last square base, so that makes 4 times) there is a steep staircase, added a bit anyway, which is sometimes blocked the passage a pipeline. This staircase leads into empty rooms mysteriously seem to have been recently refurbished (light, electrical outlets). Impossible to know what they were good or what they will be used, it is already difficult to access with empty hands, imagine the trouble we have to make a table! No other access to these rooms, no windows.

On the top of the Lantern tower, in the center of the cathedral. The main towers behind, in the front of the cathedral are empty.

The courthouse in Brussels is particularly empty. A room located just beneath the great dome lets take this view from above.