As early as 1905, Princess Maria Luisa Boulevard became the city’s first paved boulevard, covered with carefully laid granite paving stones. The benefits of high-quality road surfacing were appreciated by the city’s residents, and gradually the main roads in the capital were paved in the same way.

In the 1920s, a stone quarry opened in the village of Vladaya, where paving stones began to be produced to meet the needs of the growing town. Small, medium and large – hand-carved at first, then using stone-cutting machines. In 1934, the mayor, engineer Ivan Ivanov, signed a contract for the supply of 5 million paving stones from the ‘Kamenodelets’ cooperative. Things were done on a grand scale – by the end of the decade, Sofia was laying between 7 and 10 million paving stones a year. Experienced pavers lay this urban art on their knees, using their hands and a hammer.

Tsar Boris III Boulevard was paved even before the Second World War. Cubic in shape, measuring around 10 by 12 cm, the paving stones there today bear witness to decades of traffic – from carts and trams to scooters and hybrid vehicles. Part of the paving has already been replaced.