The Commemorative Cross to the Romanian Heroes of the First World War, also called the Heroes’ Cross on Mount Cairaman, is a monument built between 1926 and 1928 on Caraiman Peak at an altitude of 2,291 m located in Romania, in the Bucegi Mountains of the Southern Carpathians.

The Heroes’ Cross was built between 1926 and 1928 in the memory of the railway heroes who died on duty in World War I fighting against the armies of the Central Powers. The name of the monument is “The Heroes’ Cross”, but it is popularly known as the “Cross on Caraiman”.

The Heroes’ Cross is located in the saddle of the Caraiman Mountains, on the slope of the Seacă Valley at an elevation of 2,291 meters. The cross itself has a height of 28 meters and two arms of 7 meters each. The monument is the tallest summit cross in the world situated at such an altitude. The width of the vertical pole is 2 meters; the horizontal arms have a length by spindle pole of 7 meters, and a square cross-section with sides of 2 meters.

A summit cross is a cross on the summit of a mountain or hill that marks the top. Often there will be a summit register at the cross, either in a container or at least a weatherproof case.

The cross is made out of steel profiles and is mounted on a pedestal of concrete clad with stone 7.5 meters high. Inside the pedestal, there is a room that originally housed the electric generator that powered the 120 light bulbs of 500 W each located on the perimeter of the cross.

The monument is currently administrated by the Buşteni City Council. Nowadays, at night, the Cross on Caraiman is illuminated with 300 light bulbs of 500 W each and can be seen from dozens of miles away, in the Prahova Valley. There is a new project which aims to cover the cross with a fluorescent dye and on top of the cross is a projected laser spot.

According to wikipedia