Fontanna Neptuna

A first Nordermarkt fountain was apparently built in 1595 on the Südermarkt. This first fountain, which was built at the same time as the Schrangen, had a pillared roof. The Neptune Fountain (Danish: Neptunbrønden), which today dominates the Nordermarkt, was created in 1758. The rococo fountain was created by L. Meymann.
There, since the 1980s, students at the Duborg School have undergone a "Neptune's baptism" after passing their Abitur.
At the same place, since the 2000s, souvenir hunters have increasingly stolen the gold-plated trident that King Neptune is holding. After the Neptune figure was sprayed with purple paint in the first decade after the turn of the century and its trident was broken off together with the hand, the figure remained in this state for years.

In 2013, a report by the State Office for the Preservation of Monuments determined that the fountain was severely damaged due to natural wear and tear, vandalism and vibrations in the subsoil caused by the delivery traffic for the shops.
It was not until 2015 that the fountain and the figure were extensively renovated. The newly inserted metal trident was stolen again shortly after. Since then, the Flensburg Beautification Association has replaced the trident with a copy made of cast resin, which, however, has predetermined breaking points so that vandalism does not lead to further damage to the limbs. In the past, the Flensburg Beautification Association called for video surveillance and a wreath with sixty centimeter long steel spikes and a ban mile to permanently end vandalism to protect the cultural monument.

dewiki.de/Lexikon/Nordermarkt#Neptunbrunnen

"Small Fountain at Nordermarkt"
The well-attended historical Nordermarkt, which is a popular meeting place for Flensburg residents with its street cafés and pubs near the Marienkirche, is close to the Schrangen and the two-storey eaves houses, which are well worth seeing. The small fountain was built from sandstone in 1758 by L.M.Sch.Neumann. It is a fine example of the fountains that used to be common in Flensburg. The rococo-style work shows the Danish national coat of arms and the monogram of King Frederick V, which expresses the bond with the neighboring country. Gold-crowned Neptune is enthroned at the top.
Source: cityseeker.com/de/flensburg/242240-neptunbrunnen

The heart of the Nordermarkt is undoubtedly the Neptune Fountain. With its Rococo appearance and impressive presence, it stands as a symbol of Flensburg's connection to the sea. The Neptune Fountain was created in 1758 and is now one of the most important sights and landmarks in Flensburg. The Neptune Fountain not only tells of past artistry, but also of a special tradition – the “Baptism of Neptune”, in which high school graduates from Duborg-Skolen go through a symbolic ceremony after graduating.But the history of the Neptune Fountain also has everyday dark sides. Vandalism and theft continue to threaten the figure of Neptune, and it took intensive efforts to restore the fountain to its former glory. The Flensburg Beautification Association is committed to protecting this cultural heritage. Even measures such as video surveillance and special protective devices are being discussed.(weites.land/nordermarkt-flensburg/)