Kiel Canal in the context of "Canal age"

Jutland (/ˈdʒʌtlənd/), historically known as the Cimbrian Peninsula, is a peninsula in Northern Europe that forms the continental portion of Denmark and part of northern Germany (Schleswig-Holstein). It stretches from the Grenen spit in the north to the confluence of the Elbe and the Sude in the southeast. The historic southern border river of Jutland as a cultural-geographical region, which historically also included Southern Schleswig, is the Eider. The peninsula, on the other hand, also comprises areas south of the Eider: Holstein, the former duchy of Lauenburg, and most of Hamburg and Lübeck.

Jutland's geography is flat, with comparatively steep hills in the east and a barely noticeable ridge running through the center. West Jutland is characterised by open lands, heaths, plains, and peat bogs, while East Jutland is more fertile with lakes and lush forests. The southwestern coast is characterised by the Wadden Sea, a large, unique international coastal region stretching through Denmark, Germany, and the Netherlands. The peninsula's longest river is the Eider, which rises close to the Baltic but flows in the direction of the North Sea due to a moraine, while the Gudenå is the longest river of Denmark. In order for ships not having to go around the whole peninsula to reach the Baltic, the Kiel Canal – the world's busiest artificial waterway, crossing the peninsula in the south – was constructed.

Cuxhaven (German: [kʊksˈhaːfn̩] ; Low German: Cuxhoben) is a port town and seat of the Cuxhaven district, in Lower Saxony, Germany. The town includes the northernmost point of Lower Saxony. The city serves as a gateway to the nearby Heligoland islands, a tax free zone off the coast of Germany. Cuxhaven is situated on the shore of the North Sea at the mouth of the Elbe River. Cuxhaven has a footprint of 14 kilometres (9 miles) (east–west) by 7 km (4 mi) (north–south). Its town quarters Duhnen, Döse and Sahlenburg are especially popular vacation spots on the North Sea and home to about 52,000 residents.

Cuxhaven is home to an important fisherman's wharf and ship registration point for Hamburg as well as the Kiel Canal until 2008. Tourism is also of great importance. The city and its precursor Ritzebüttel belonged to Hamburg from the 13th century until 1937. What remains of Ritzebüttel is Ritzebüttel Castle ('Schloss Ritzebüttel'). The island of Neuwerk, a Hamburg dependency, is located just northwest of Cuxhaven in the North Sea. The city's symbol, known as the Kugelbake, is a beacon once used as a lighthouse; the wooden landmark on the mouth of the Elbe marks the boundary between the river and the North Sea and also adorns the city's coat of arms.

Kiel (/kiːl/ KEEL; German: [kiːl] ) is the capital and most populous city in the northern German state of Schleswig-Holstein. With a population of around 250,000, it is Germany's largest city on the Baltic Sea. It is located on the Kieler Förde inlet of the Bay of Kiel and lies in the southeast of the Jutland Peninsula, on the mouth of the Schwentine River, approximately 90 kilometres (56 mi) northeast of Hamburg. The world's busiest artificial waterway, the Kiel Canal, has a terminus in Kiel's Holtenau district. This canal connects the Baltic to the North Sea, with its other end in Brunsbüttel. Most of Kiel is part of Holstein. The boroughs north of the Schwentine also belong to Wagria, while those north of the Kiel Canal are historically part of Southern Schleswig.

Originally a small settlement, Kiel was granted city rights in 1242. Over the centuries, it developed as an important port and trading hub, particularly due to its strategic location on the Kieler Förde inlet. Kiel became part of the Duchy of Holstein, the northernmost state of the Holy Roman Empire. From 1773 to 1864, it was ruled in personal union by the king of Denmark. In 1864, after the Second Schleswig War, the city was incorporated into the Kingdom of Prussia. During the 20th century, Kiel played a significant role in both World War I and World War II, with its naval significance and shipbuilding industry. Following World War II, it became part of West Germany and later the unified Germany.

Øresund or Öresund (UK: /ˌɜːrəˈsʊnd/, US: /ˈɜːrəsʌn, -sʊnd, ˈɔːrəsʊnd/; Danish: Øresund [ˈøːɐˌsɔnˀ]; Swedish: Öresund [œːrɛˈsɵnːd]), commonly known in English as the Sound, is a strait which forms the Danish–Swedish border, separating Zealand (Denmark) from Scania (Sweden). The strait has a length of 118 kilometres (73 mi); its width varies from 4 kilometres (2.5 mi) to 28 kilometres (17 mi). The narrowest point is between Helsingør in Denmark and Helsingborg in Sweden.

Øresund, along with the Great Belt, the Little Belt and the Kiel Canal, is one of four waterways that connect the Baltic Sea to the Atlantic Ocean via Kattegat, Skagerrak, and the North Sea; this makes it one of the busiest waterways in the world.

The Eider (German: Eider [ˈaɪdɐ] ; Danish: Ejderen; Latin: Egdor or Eidora) is the longest river in the German state of Schleswig-Holstein. The river starts near Bordesholm and reaches the southwestern outskirts of Kiel on the shores of the Baltic Sea, but flows to the west, ending in the North Sea. The lower part of the Eider was used as part of the Eider Canal until that canal was replaced by the modern Kiel Canal.

In the Early Middle Ages the river is believed to have been the border between the related Germanic tribes, the Jutes and the Angles, who along with the neighboring Saxons crossed the North Sea from this region during this period and settled in England. During the High Middle Ages the Eider was the border between the Saxons and the Danes, as reported by Adam of Bremen in 1076. For centuries it divided Denmark and the Holy Roman Empire. Today it is the border between Schleswig, Holstein and Eiderland, the northern and southern parts, respectively, of the modern German state of Schleswig-Holstein.