Yenikapı (Turkish pronunciation: [jenikapɯ]) is a port and a quarter in Istanbul, Turkey, in the metropolitan district of Fatih on the European side of the Bosphorus and along the southern shore of the city's historically central peninsula.
Yenikapı is notable for the ongoing excavations on its Byzantine port discovered in 2004. This has become one of the largest investigations in Europe, because of the size and the number of the shipwrecks found since the initial discovery, and the large number of associated artefacts. The commercial harbor, called the Harbour of Theodosius, in use between the 5th and the 10th centuries, was an alternative to Constantinople's traditional berths situated along the inlet of the Golden Horn.
The Yenikapı Transfer Center is also the site of an underground mass rapid transit terminal, construction of which was delayed by the massive excavations necessary for the project. The new Yenikapi terminal provides interchanges between the Hafif Metro (M1) line that connects to the airport, the Istanbul Metro's M2 line, and the new Marmaray railway link connecting the Asian and European sides of the city through a new tunnel under the Bosporus.
During the archaeological excavation at the Yenikapı Marmaray construction site, it has been learned that Istanbul's history dates back further than was previously thought, some 8,500 years.
8,000-year-old skeletons were discovered and with the continuous excavations further graves have been unearthed. The graves reveal that Istanbul used to be home to the earliest settlements during the Stone Age. The skeletons were found in four prehistoric graves.
Other than skeletons, the digs have revealed 34 sunken ships dating back to the seventh and 11th centuries. The sunken ships have been conserved at the Istanbul University and the Underwater Research Institute in Bodrum.
About 500 pieces taken from the relics unearthed during the Marmaray excavations were exhibited at the Istanbul Archeology Museum.
In order to provide an adequate urban and architectural design for the archaeological site, an international design competition was organized in 2012, with the project by Peter Eisenman and Aytac architects eventually selected as the winning proposal. The project also envisages the realization of an archeo-park and a large archaeological museum. 
- "La Turquie s’intéresse à son archéologie" (in French). La Croix. 2008-01-04.
- "A never-ending story of Istanbul's 8,500-year history". Hurriyet. 2009-02-01.
- Saudi Aramco World: Uncovering Yenikapi