At the [Furlo Pass][1] in the Apennines, the [Via Flaminia][2] passes through a tunnel built in 76 - 77 AD during the time of Emperor [Vespasian][3], replacing an earlier tunnel. [![Via Flaminia tunnel][4]][4] *[The tunnel built during the time of Vespasian][5]. Attrib: By AlMare (Own work) [CC BY-SA 2.5 (https://creativecommons.org/licenses/by-sa/2.5)], via Wikimedia Commons* This earlier, smaller (first) tunnel is "apparently of the 3rd century BC" according to the Wikipedia articles on [Tunnels][6] and the Via Flaminia, with the former article stating this is "*one* of the first road tunnels" (my highlighting). The article on the Furlo Pass states this smaller tunnel dates "from Etruscan times", as does the article on the [Apennine Mountains][7] Did the [Etruscans][8] really build a tunnel here and, if so, is it the first known road tunnel built? If not, what is the earliest known road tunnel built under or through a natural formation (i.e. not under or through a man-made construction)? **EDIT** In his answer, Alex makes the valid point that it is not exactly clear what a road is. There are various definitions depending on what source one looks at. [Merriam-Webster][9] has "an open way for vehicles, persons, and animals" while [Oxford][10] offers "A wide way leading from one place to another, especially one with a specially prepared surface which vehicles can use" (Collins and Cambridge have similar definitions). There's also this from [Wikipedia][11]: "A road is a thoroughfare, route, or way on land between two places that has been paved or otherwise improved to allow travel by foot or some form of conveyance". For the purposes of this (historical) question, it seems reasonable to accept answers which fall within the broader (Wikipedia / Merriam-Webster) definitions. However, I would exclude tunnels built for mining. [1]: https://en.wikipedia.org/wiki/Furlo_Pass [2]: https://en.wikipedia.org/wiki/Via_Flaminia [3]: https://en.wikipedia.org/wiki/Vespasian [4]: https://i.sstatic.net/fNiUk.jpg [5]: https://commons.wikimedia.org/wiki/File:Furlo_Tunnel_North.jpg [6]: https://en.wikipedia.org/wiki/Tunnel#Antique_and_early_middle_ages [7]: https://en.wikipedia.org/wiki/Apennine_Mountains [8]: https://en.wikipedia.org/wiki/Etruscan_civilization [9]: https://www.merriam-webster.com/dictionary/road [10]: https://en.oxforddictionaries.com/definition/road [11]: https://en.wikipedia.org/wiki/Road