Water tower, Langeoog, Cultural heritage monument in Langeoog, Germany.

The water tower of Langeoog is a concrete and brick construction that rises prominently above the flat island landscape, distinguished by its slender form. The structure was originally designed for water storage and supply of the settlement and features a characteristic layout with a tank at the top and supporting base below.

In 1908 the Langeoog council contracted the Berlin-Anhaltische Maschinenbau Actien-Gesellschaft to build a water supply and sewage system, financed by a spa tax introduced in 1906. On 16 February 1909 the wooden Westkaap beacon was demolished and the tower's foundation stone laid on the same spot. The tower was taken out of service in the late 1980s and fully restored in 1994 and from October 2008 to May 2009.

The tower shapes the island's appearance as a modern structure from Langeoog's early development period. Its visual presence and location make it an anchor point that people notice and remember when moving through the settlement.

The tower stands at the end of the island village's main street on the Kaapdünen dunes, reached by a footpath and stairway near the path linking the village to the beach. The viewing platform sits 23 metres above sea level. The lower floor holds a small free exhibition on the island's water supply, and entry is free.

The tower was originally meant to carry an upside-down triangle as a daymark, echoing the wooden beacon Westkaap demolished on the same dune on 16 February 1909. The idea was dropped because the building was already unmistakable. Its eight-sided tank floor, holding about 100 cubic metres, projects well beyond the brick base.