Most of Romania's tunnels date from the 20th century in the building of the railways, typically excavated through rock by blasting and then hand excavation.
The more modern tunnels include the longer Bucharest metro tunnels and utility tunnels, constructed from approximately 1970 to date, using a variety of tunnelling methods.
^^ Michael Wedekind: Der Siebenbürgische Karpatenverein (1880–1944). Ein Beitrag zur sozialgeschichte Siebenbürgens. Westfälische Wilhelms Universität Münster 2004, p. 7.