A tourist checks the installation "Keeper of Time" in front of the illuminated Berlin Cathedral during the 9th Berlin Festival of Lights in Berlin, Germany, on Oct. 9, 2013. The festival, held from Oct. 9 to Oct. 20, transforms Berlin's world famous landmarks, cultural monuments, historical buildings, streets and other locations with light. (Xinhua/Zhang Fan)

A tourist walks past the illuminated Palace of Festungsgraben during the 9th Berlin Festival of Lights in Berlin, Germany, on Oct. 9, 2013. The festival, held from Oct. 9 to Oct. 20, transforms Berlin's world famous landmarks, cultural monuments, historical buildings, streets and other locations with light. (Xinhua/Zhang Fan)

Two people stand in front of the illuminated Hotel de Rome during the 9th Berlin Festival of Lights in Berlin, Germany, on Oct. 9, 2013. The festival, held from Oct. 9 to Oct. 20, transforms Berlin's world famous landmarks, cultural monuments, historical buildings, streets and other locations with light. (Xinhua/Zhang Fan)

A boy watches with his parents the opening ceremony of the 9th Berlin Festival of Lights at the Potsdamer Platz square in Berlin, Germany, on Oct. 9, 2013. The festival, held from Oct. 9 to Oct. 20, transforms Berlin's world famous landmarks, cultural monuments, historical buildings, streets and other locations with light. (Xinhua/Zhang Fan)

The Berlin Cathedral is illuminated during the 9th Berlin Festival of Lights in Berlin, Germany, on Oct. 9, 2013. The festival, held from Oct. 9 to Oct. 20, transforms Berlin's world famous landmarks, cultural monuments, historical buildings, streets and other locations with light. (Xinhua/Zhang Fan)

Part of the light art "Festival of Lights 2013" is seen on a building during the opening ceremony of the 9th Berlin Festival of Lights at the Potsdamer Platz square in Berlin, Germany, on Oct. 9, 2013. The festival, held from Oct. 9 to Oct. 20, transforms Berlin's world famous landmarks, cultural monuments, historical buildings, streets and other locations with light. (Xinhua/Zhang Fan)