Holmen Naval Base

Since the city was growing, it was not practical to have the Navy Fleet stationed in the centre of the city. The ships were, of course, built out of wood and were fire hazards. The seamen on the ships simply threw their waste and trash directly into the harbor, which had a negative impact on the city's health.

In 1680, a plan was made to move the fleet out of the city. Responsibility for the plan was given to Admiral Niels Juel. West of a sandbank called Revshalen, old ships were scuttled after being filled with stones. In 1685, a defence wall with seven bastions was built. The bastions still exist today, and in Carls and Wilhems Bastion, one can still see the original black powder depots. These depots are Holmen's oldest buildings, built in 1688 and 1690. The northern bastion was Charlotte Amalies Bastion, and north of this two cannon batteries were established, "Batteriet Quintus" and "Batteriet Neptunus". The latter's name came from the sunken ship which was the foundation for the battery. This battery was later renamed to "Christiani Sixti Batteri", or "Christian the Sixth's Battery", but is known today as "Batteriet Sixtus" or just "Sixtus". The sinking of ships continued, filled with mud from the harbor and the trash from Copenhagen's streets. In certain streets, there was over a meter of trash, so there was plenty to take. This is how the island given the name Nyholm was created.

On Nyholm, the foundation for a new shipyard was created. The first ship which was set to sea from this shipyard was Dannebrog in 1692. This ship was blown up on October the 4th, 1710, in a battle against the Swedes in Køge Bugt. Afterwards, the constructions of all large ships were moved to Nyholm, and on Gammelholm, only smaller ships were built.

After 1692, several ships were built on Nyholm and in 1750, a Danish king, then Frederik V, wore a naval uniform for the first time in connection with the christening of a new ship. In 1807, following the Second Battle of Copenhagen, the English destroyed three ships within the shipyard at Nyholm, but even though these were poor times for the Navy, ship construction continued at Nyholm. The last ship to be launched from Nyholm was launched in 1918, after which ship construction and several other operations were moved to Frederiksholm, which was to the south. The shipyard was separated from the Navy and became a civilian operation with its own director.

Holmen's southernmost island is Arsenaløen, or Arsenal Island.

While development on Nyholm was continuing, a little island by the name of Motzmanns Plads, just north of Christianshavn, was bought. Later it was renamed to Christiansholm. A new island was created, with landfill, just east of Christianholm, where a large arsenal was built and finished in 1770. Later, this island was named Arsenaløen and was expanded to the east.

The King's Gate. The gate has recently been restored, but is still hidden behind Christiansholm.

Originally, a main gate existed to Nyholm. Nyholm wasn't just a name for the northernmost island but was the name for the area used by the navy. Access to the area required sailing to Holmen. A ferry sailed to Christiansholm, where one went over a bridge to Arsenaløen. Here, one could go to Nyholm though a gate, which faced the canal between Arsenaløen and Christiansholm. The gate was called "The Kings Gate". It is not visited by many people anymore. This is because in the middle of the 19th century, Arsenaløen formed a land connection with Christianshavn, so a new main entrance was created to Holmen, the so-called Warf Bridge Guard, or Værftsbrovagt. The ferry to Christiansholm stopped and the Kings Gate was no longer used.

Around 1750, dumping of dirt and fill created two small islands south of Nyholm, "Ballastøen" and "Ankerøen", along with a larger island, "Langøen". From Nyholm, a bridge was built to Ballastøen and from Ballastøen to Ankerøen and from Ankerøen to Langøen. From Langøen's southern end, a bridge was built to Arsenaløen. This happened in the later part of the 18th century. At this point, all of Holmen's islands were connected. East from Langøen, an atoll was found called "Mudderøen"; the area between Mudderøen (including Mudderøen itself) and Langøen was filled, and "Frederiksholm" was created. This area was supposed to become a residential area for Navy personnel, but this plan was never followed through. Instead, the area became a storage area for ship masts, along with a row of other buildings on the island. After the Gunboat War, slips were made for the storage of cannon ships. When Nyholm, as mentioned, was expanded together with Ballastøen and Ankerøen to present day Nyholm, Ankerøen and Ballastøen were replaced with Ballasø and Ankerø, which were created west of Frederiksholm.