Lange Jaap ("Tall Jacob"), also known as Kijkduin Light or Den Helder Light, is an active lighthouse near Fort Kijkduin in Huisduinen, Netherlands. At a height of 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 site used to be open and accessible to visitors. Due to safety concerns, the tower itself has been closed to the public since 1998. Since September 2021, an area with a radius of 70 meters around the lighthouse has been fenced off due to concerns that the tower may topple over. History The first aid to navigation at the site was a simple coal-fire light from 1814, at Fort Kijkduin, a few hundred meters north 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 -tall, six-storey brick tower. The light consisted of 26 Argand lamps with parabolic reflectors, visible at a distance of up to . 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 2 September 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