The suez canal was built on the isthmus of suez and connected the

Connected the Mediterranean sea to the red sea.

The Mediterranean the Red Sea, is the right answer.

Explanation:

The Suez Canal is a caliber water-route located in Egypt, which connects two major seas known as the Mediterranean the Red Sea. This canal was built in the years between 1859-1869 by the Suez Canal Company. Officially this canal was opened on November 17th, 1869. The canal contributes watercraft a major direct route connecting the North Atlantic and north Indian waters through the Mediterranean and Red sea.