|Year first constructed||1822 (first)|
|Year first lit||1878 (current)|
|Construction||cast iron tower|
|Tower shape||16-sided tapered prism with gallery, lantern and rotating antenna|
|Markings / pattern||red tower and dome, white lantern|
|Tower height||55.5 metres (182 ft)|
|Focal height||57 metres (187 ft)|
|Original lens||1st order Fresnel lens|
|Range||30 nautical miles (56 km; 35 mi)|
|Characteristic||Fl (4) W 20s.|
Lange Jaap ("Long Jeep"), also known as Kijkduin Light or Den Helder Light, is an active lighthouse near Fort Kijkduin in Huisduinen, Netherlands. At a height of 55 metres (182 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. That may be the case if the height is as specified in that source (63.5 metres (208 ft)). However, if the height is 55.5 metres (182 ft), as stated by other sources, it is the second tallest, Cikoneng Light being 58 m (190 ft).
The site is open and accessible to visitors. Due to safety concerns, however, the tower itself has been closed to the public since 1998.
The first aid to navigation at the site was a simple coal-fire light from 1814, at Fort Kijkduin, a few hundred meters south of the current tower. In 1822 the construction of the first tower was completed and it was first lit on 29 October 1822. The tower was a 22 metres (72 ft)-tall, six-storey brick tower. The light consisted of 26 Argand lamps with parabolic reflectors, visible at a distance of up to 6 nautical miles (11 km; 6.9 mi). Cracks in the building foundation were repaired twice, in 1826 and 1827. In 1853 the light was replaced by an Argand lamp lens system with fixed Fresnel lens.
The construction of the second and current lighthouse started in 1877 and its first illumination was on 1 April 1878. The first lens system was a stationary lens with Argand lamps from the old tower. In 1903 this was replaced with a Barbier and F.B. rotational system, with Mercury bearings. It used incandescent kerosene and had an intensity of 1,200,000 cd. Its characteristic was 2 flashes every 10s and was visible for "20 English miles".
In 1912 an improved pharoline incandescent light was installed. The light was electrified in 1924 and a Brandaris 80V 50A lamp was fitted. In 1940, during World War II, this light system was destroyed. During the war the lighthouse was painted in camouflage-colours. An emergency light was installed in 1945, with an intensity of 62,000 cd. On September 2, 1949 the current 920mm 1st order Fresnel lens was installed.
In 1988 the site was listed as a Rijksmonument. The cupola and lantern pane were replaced in 1992; the old shell is displayed outdoors in the royal dockyard of Willemsoord in Den Helder. In 1998 the lighthouse was closed to the public due to cracks on the cast-iron floors. Although it was refurbished in 1999 and a new coat of paint was applied, as of 2002 it is unlikely that the tower will be reopened, especially due to more stringent safety regulations introduced after the Volendam café disaster and the formation of the Dutch Safety Board.