Tohid Tunnel

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Tohid (or Towheed) Tunnel is a tunnel in Tehran, Iran, the third longest urban tunnel in the Middle East. Towheed Tunnel Project is an urban underground structure, located within the area of Chamran Highway, Towheed Square, Jomhouri Square, and Navab Highway, with a length of about 3 km (Tunnel + entry ramps). Tohid Tunnel broke construction records when it was opened in less than 30 months. The interior designs met the highest safety requirements.^[1] It includes installation of utilities equipment in the Tunnel, and manufacture and mobilization of north and south fans combined ventilation equipment, and control building and Niyayesh shaft.