Which sea strait separates Denmark from Norway and Sweden?

The Skagerrak is a strait running between the southeast coast of Norway, the west coast of Sweden, and the Jutland peninsula of Denmark, connecting the North Sea and the Kattegat sea area, which leads to the Baltic Sea.

The Skagerrak contains some of the busiest shipping routes in the world, with vessels from every corner of the globe. It also supports an intensive fishing industry. The ecosystem is strained and negatively affected by direct human activities. Oslo and Gothenburg are the only large cities in the Skagerrak region.

The Skagerrak is 240 km (150 mi) long and between 80 and 140 km (50 and 87 mi) wide. It deepens toward the Norwegian coast, reaching over 700 m (2296 ft) at the Norwegian Trench. Some ports along the Skagerrak are Oslo and Kristiansand in Norway and Uddevalla, Lysekil and Stromstad in Sweden.

Skagerrak is popular for recreational activities in all three countries. There are many summer house residences and several marinas along the coasts.

With the centuries long heavy international sea traffic of Skagerrak, the seabed also holds an abundance of shipwrecks. Wrecks on shallow waters, provides a firm anchoring for several corals and polyps and explored wrecks have been revealed to support Dead Man's Fingers corals, Brittle stars and large Wolffish.