The Terneuzen lock complex or Sea locks in Terneuzen is a lock complex that provides access from the Western Scheldt to the Canal from Ghent to Terneuzen and thus to the port of Ghent. The canal was constructed between 1823 and 1825 and ended in the Western Scheldt . Two locks were constructed near Terneuzen, one of 8 meters wide and one of 12 meters wide. The locks have been improved and enlarged several times. The complex now consists of three locks. The oldest, the Middensluis, opened in 1910, has a length of 140 meters and a width of 18 meters. At the end of the 60s of the 20th century, extensive works took place which resulted in the opening of two new locks in 1968:

– The East lock or inland waterway lock, with a length of 280 meters and a width of 23 meters.

– The Western lock or sea lock, with a length of 290 meters and a width of 40 meters. This lock is suitable for seagoing vessels with a draft of up to 12.5 meters and a loading capacity of 83,000 tonnes. Provisions have been made at the lock to prevent salt water from entering the canal. Belgium had a share of 80% of the total construction costs of the Western lock; The Netherlands paid the remaining 20%.

Every year about 10,000 sea-going vessels, over 50,000 inland vessels and 3,000 pleasure craft pass through the locks.