The Russians built the first oil-distilling factory in Balaxani in 1837. Digging for oil began in the mid-1800s, with the first oil well drilled in the Bibi-Heybat suburb of Baku in 1846. It was mechanically drilled, though a number of hand-dug wells pre-dated it. Large-scale oil exploration started in 1872 when Russian imperial authorities auctioned parcels of oil-rich land around Baku to private investors. The pioneer of oil extracting from the bottom of the sea was the Polish geologist Witold Zglenicki. Soon after, investors appeared in Baku, including the Nobel Brothers in 1873 and the Rothschilds in 1882. An industrial area of oil refineries, better known as Black Town (), developed near Baku by the early 1880s.