Shenzhen Bay Port is a juxtaposed border crossing and a port of entry and exit between mainland China and the Hong Kong Special Administrative Region, located geographically in Dongjiaotou, Shekou, which lies on the southwestern corner of the city of Shenzhen in Guangdong Province.

Juxtaposed controls are a reciprocal arrangement between Belgium, France, the Netherlands and the United Kingdom whereby border controls on certain cross-Channel routes take place before boarding the train or ferry, rather than upon arrival after disembarkation. With the exception of the Eurotunnel Shuttle route, customs checks remain unaffected by juxtaposed immigration controls and continue to take place upon arrival after disembarkation. Belgium, France and the Netherlands are all member states of the European Union and part of the border-free Schengen Area. The United Kingdom, on the other hand, has never participated in the Schengen Area, even when it was a member state of the European Union. As a result, juxtaposed controls aim to increase the convenience and efficiency of border checks when travelling by train or ferry between the Schengen Area and the UK by removing the need for immigration checks on arrival and by streamlining checks on departure. At the same time, juxtaposed controls are intended to detect and prevent illegal immigration. In 2016, there were over 56,000 instances when people were refused entry to the UK at the juxtaposed controls.