International waterway in the context of "Estuaries"

The Dardanelles (/ˌdɑːrdəˈnɛlz/ DAR-də-NELZ; Turkish: Çanakkale Boğazı, lit. 'Strait of Çanakkale'; Greek: Δαρδανέλλια, romanized: Dardanéllia), also known as the Strait of Gallipoli (after the Gallipoli peninsula) and in classical antiquity as the Hellespont (/ˈhɛlɪspɒnt/ HEL-isp-ont; Classical Greek: Ἑλλήσποντος, romanized: Hellḗspontos, lit. 'Sea of Helle'), is a narrow, natural strait and internationally significant waterway in northwestern Turkey that forms part of the continental boundary between Asia and Europe and separates Asian Turkey from European Turkey. Together with the Bosporus, the Dardanelles forms the Turkish Straits.

One of the world's narrowest straits used for international navigation, the Dardanelles connects the Sea of Marmara with the Aegean and Mediterranean seas while also allowing passage to the Black Sea by extension via the Bosporus. The Dardanelles is 61 kilometres (38 mi) long and 1.2 to 6 kilometres (0.75 to 3.73 mi) wide. It has an average depth of 55 metres (180 ft) with a maximum depth of 103 metres (338 ft) at its narrowest point abreast the city of Çanakkale. The first fixed crossing across the Dardanelles opened in 2022 with the completion of the 1915 Çanakkale Bridge.

The Bosporus or Bosphorus Strait (/ˈbɒspərəs, ˈbɒsfərəs/ BOSS-pər-əs, BOSS-fər-əs; Turkish: İstanbul Boğazı, lit. 'Istanbul strait', colloquially Boğaz) is a natural strait and an internationally significant waterway located in Turkey which is straddled by the city of Istanbul. The Bosporus connects the Black Sea to the Sea of Marmara and forms one of the continental boundaries between Asia and Europe. It also divides Turkey by separating Asia Minor from Thrace. It is the world's narrowest strait used for international navigation.

Most of the shores of the Bosporus Strait, except for the area to the north, are heavily settled, with the city of Istanbul's metropolitan population of 17 million inhabitants extending inland from both banks.

The Danish straits are the straits connecting the Baltic Sea to the North Sea through the Kattegat and Skagerrak. Historically, the Danish straits were internal waterways of Denmark; however, following territorial losses, Øresund and Fehmarn Belt are now shared with Sweden and Germany, while the Great Belt and the Little Belt have remained Danish territorial waters. The Copenhagen Convention of 1857 made all the Danish straits open to commercial shipping. The straits have generally been regarded as an international waterway.