Restoration helps leaning tower to straighten up

It was no miracle but human effort and an exemplary achievement that the ‘ leaning tower of Pisa’ has straighten up considerably after years of hard work.  In fact a restoration work had started 17 years back . Leaning tower leans about half a degree less  and had lost 4 cms of the tilt , according to the University of Pisa. This tower which dates back to 1173 started leaning after construction.