Google Earth has made historical aerial images available that show the devastation of European Cities caused by bombing raids during World War II.

The Historical Imagery feature shows the effects on more than 35 towns and cities in Europe and lets viewers compare the destruction with images of the same areas from the present day.

Google said imagery from 1935 and 1945 for Warsaw in Poland is particularly compelling. The city, a UNESCO World Heritage site was amongst those most badly damaged in the war.

The comparisons then and now of the city, described by UNESCO as an 'outstanding example of a near-total reconstruction of a span of history covering the 13th to the 20th century' are striking.

The Royal Castle of Warsaw for example was burned to the ground and subsequently reconstructed, between 1971 and 1988.

The historical images also include shots of the location of the Warsaw Ghetto, supposedly the largest ghetto in Europe between 1940 and 1943.

To access the historical imagery feature, download Google Earth and click the clock icon in the status bar (the top-level toolbar) to activate a time-line.

Move back in forth in time by dragging the time slider from left to right or by clicking the back/forwards arrows.