![File:Tunnel in Corso d'Italia, nearby Porta Pinciana under the Aurelian Walls, Rome.jpg - Wikimedia Commons File:Tunnel in Corso d'Italia, nearby Porta Pinciana under the Aurelian Walls, Rome.jpg - Wikimedia Commons](https://upload.wikimedia.org/wikipedia/commons/3/3d/Tunnel_in_Corso_d%27Italia%2C_nearby_Porta_Pinciana_under_the_Aurelian_Walls%2C_Rome.jpg)
File:Tunnel in Corso d'Italia, nearby Porta Pinciana under the Aurelian Walls, Rome.jpg - Wikimedia Commons
![Porta Westfalica, Germany. 07th May, 2016. Visitors walk through a former tunnel below Jakobsberg hill in Porta Westfalica, Germany, 07 May 2016. The tunnel was enlarged during World War Two by inmates Porta Westfalica, Germany. 07th May, 2016. Visitors walk through a former tunnel below Jakobsberg hill in Porta Westfalica, Germany, 07 May 2016. The tunnel was enlarged during World War Two by inmates](https://c8.alamy.com/comp/G11BK4/porta-westfalica-germany-07th-may-2016-visitors-walk-through-a-former-G11BK4.jpg)
Porta Westfalica, Germany. 07th May, 2016. Visitors walk through a former tunnel below Jakobsberg hill in Porta Westfalica, Germany, 07 May 2016. The tunnel was enlarged during World War Two by inmates
![Description of the construction to the Porta Alpina, the underground train stop in the Gotthard base tunnel, Sedrun, Grisons, S Stock Photo - Alamy Description of the construction to the Porta Alpina, the underground train stop in the Gotthard base tunnel, Sedrun, Grisons, S Stock Photo - Alamy](https://c8.alamy.com/comp/AKXCP1/description-of-the-construction-to-the-porta-alpina-the-underground-AKXCP1.jpg)