Teheranno (alternatively Teheran-ro or Tehran-ro, English: Tehran Avenue, Persian: خیابان تهران) is an avenue in Seoul Gangnam-gu, South Korea. It runs from Gangnam Station through Yeoksam-dong and into Samseong-dong. It is colloquially known as “Tehran Valley” (after Silicon Valley) due to the number of internet-related companies operating there, including major domestic internet portals Daum and Naver as well as Google Korea. Samsung Electronics and SK Hynix Semiconductors both operate offices here as well. Various Korean and international financial and business institutions including POSCO, Standard Chartered-First Bank of Korea and Citibank Korea also maintain offices here. Some of Korea's tallest skyscrapers and most expensive real estate are on Teheranno, while Seoul Metropolitan Government estimates that more than half of Korea's venture capital, some 200 billion won (approximately $200 million), is invested in Tehran Valley.
Teheranno is a 3.7 km section of Korean Highway 90, and runs eastwards from Gangnam Station (Gangnam-yeok Sageori) to Samseong Station, the COEX/KWTC complex and Samseong Bridge (Samseong-gyo). Yeoksam and Seolleung stations are also on Teheranno. All stations are on Seoul Metro Line 2. This avenue consists 10 lanes, 5-lane each on two directions.
In 1976, the Seoul Metropolitan Government suggested that the city of Seoul and Tehran, pre-revolutionary Iran exchange the names of streets on the occasion of the visit to Korea of Gholamreza Nikpay, Mayor of Tehran. The following year, the street previously named Samneungno (삼릉로/三陵路) was renamed Teheranno, which ran through a relatively underdeveloped area recently annexed into Seoul (in 1963).
In the following years, the district of Gangnam-gu experienced phenomenal growth and waves of construction that continues even today, with Teheranno becoming one of the busiest streets in South Korea. Seoul St. in Tehran runs in the north of that city, close to the Evin district.
Four Intersections of Gangnam Station (Gangnam-yeok Sageori) - Four Intersections of Kukkiwon, World Taekwondo Headquarters (Kukkiwon-sageori) - Yeoksam Station - Renaissance Seoul Hotel - Seolleung Station (Joseonese Royal Tomb of Seonjeongneung) - Four Intersections of POSCO (POSCO-sageori) - Samseong Station - Gangnam Police Station, Gangnam Fire Station - Samseong Bridge