Den Helder is a municipality and a city in the Netherlands, in the province of North Holland. Den Helder occupies the northernmost point of the North Holland peninsula. It is home to the country's main naval base. From here the Royal TESO ferryboat service operates the transportation link between Den Helder and the nearby Dutch Wadden island of Texel to the north.

De Kooy Airfield is an airfield 2.9 NM south of Den Helder, Netherlands, named after the nearby hamlet De Kooy. It serves as both a civilian airport under the name Den Helder Airport and a naval airport under the name Maritiem Vliegkamp De Kooy.

Den Helder is a Terminus railway station in the naval town of Den Helder, The Netherlands. The station opened on 20 December 1865, and is the most northerly station in North Holland. The station is the start of the Den Helder–Amsterdam railway. The original station building was demolished in 1958 and a new building was built a bit further south than previous.

The Balgzand Gas Plant is a natural gas processing plant (gasbehandelingsinstallatie) in the Netherlands.

Lange Jaap, also known as Kijkduin Light or Den Helder Light, is an active lighthouse near Fort Kijkduin in Huisduinen, Netherlands. At a height of 63.5 metres (208.2 ft) it is one of the tallest "traditional lighthouses" in the world. For almost a century, from 1878 to 1974, it was the tallest lighthouse in the Netherlands, until the construction of the Maasvlakte Light. According to The Lighthouse Directory it is the tallest non-skeletal cast iron lighthouse in the world.

The Marsdiep is a deep tide-race between Den Helder and Texel in the Netherlands, and running southwards between sandbanks. That gap connects the North Sea and the Waddenzee.

Nieuwe Haven is a Royal Netherlands Navy base in Den Helder and the largest harbor in the Netherlands.
The Royal Naval College was the service academy of the Royal Netherlands Navy. From 2005 it is part of the Koninklijk Instituut voor de Marine as part of the Nederlandse Defensie Academie in Den Helder. It offers a program of four or five years and also a short course of 16 to 22 months. Upon the completion of the program a graduate is awarded a bachelor's degree and is commissioned in the Royal Netherlands Navy. The training of officers for the Royal Netherlands Army and Royal Netherlands Air Force is done by the Koninklijke Militaire Academie in Breda.

Willemsoord is a large former Naval base of the Royal Netherlands Navy in Den Helder. It is now a maritime museum, housing the Dutch Navy Museum and the Nationaal Reddingmuseum Dorus Rijkers. In 2009 the replica of the Dutch East India Company ship Prins Willem which was located in a dock burned down.