The Zero Kilometre Stone is a 3 m high limestone sculpture in Budapest, forming a zero sign, with an inscription on its pedestal reading "KM" for kilometres. This stone marks the reference point from which all road distances to Budapest are measured in the country. The reference point had initially been located at the threshold of Buda Royal Palace, but was moved to its present location by Széchenyi Chain Bridge when the crossing was completed in 1849.