There is the second-largest bridge in the world here. The so-called Öresund Bridge is 7845 meters long and connects Copenhagen with Malmö, Sweden.

An excerpt from the article 26 facts about Copenhagen

The first concepts for the construction of the bridge were created in the mid-1930s, but construction began on October 18, 1995. The bridge was completed on August 14, 1999, and the investment cost was over DKK 30 billion. The investment is expected to pay off only around 2030.