Scientists finally discover how the Leaning Tower of Pisa stays intact

The Leaning Tower of Pisa has always been a baffling mystery for scientists.

Even though the 58-metre tall tower leans at a five-degree angle, it has survived four earthquakes since 1280 with not one scratch on it.

How has it managed to stay intact? The answer may be the soil.

Dynamic soil-structure interaction (DSSI) is what a research team attributes to its survival, the Daily Mail reported.

"Ironically, the very same soil that caused the leaning instability and brought the Tower to the verge of collapse, can be credited for helping it survive these seismic events," lead author of the study Professor Mylonakis, of the Department of Civil Engineering at the University of Bristol, told the Daily Mail.

The team believes combination of the Tower's stiffness and the foundation soil's softness " causes the vibrational characteristics of the structure to be modified substantially, in such a way that the Tower does not resonate with earthquake ground motion", the report stated.