The size of the city with its medieval walls is still recognizable. Remains of the oldest moat are the current Oude and Nieuwe Haven. The city wall was replaced after 1572 by a fortification with five bastions according to the Old Dutch fortification system, designed by Thomas Thomasz and Adriaen Anthonisz.
After the occupation by the French in 1672 and the reconquest by Prince William III, under the leadership of Adriaan Dortsman, the fortifications that were still preserved were established, the first phase (1673-'78) following plans by Maximilian d 'Yvoy and the second (1679 -'85) to plans in which the influence of Paul Storff de Belleville is recognizable. The new fortress received a double fortification ring and canals with six bastions, six ravelins and an envelope according to the New Dutch system. At and in the bastions were bombproof barracks, casemates, depots, warehouses and potteries. Only two gates - the Utrecht and the Amsterdam gate - provided access to the fortress. The bastions Oud-Molen, Katten and Oranje formed the sea front. In order to separate the inside and outside of the dike, brick bears were built in the moat; the western bear with monks (1676, replaced 1938) and the eastern bear (1685). The Promers, Turfpoort and Nieuw-Molen bastions covered the landside.
From 1678 the Great Arsenal (Kooltjesbuurt 1) dates back to the form. tuighuis on bastion Oud-Molen. This white plastered rectangular complex has four wings around a courtyard. Above the middle round arch gate is a large sandstone relief with arms trophy and in the hall there is a marble memorial stone from 1688. In 1728 the building was raised with a floor and extended with a north-east wing, the also white plastered Klein Arsenaal. This arsenal complex, restored after a fire in 1954, has kept a military function until 1987; now there are shops.
In 1815 the Naarden fortress became part of the New Dutch Waterline. The fortifications were modernized in 1873-'79. For example, the Utrechtse Poort was renewed and between Fortress and Zuiderzee the Fort Ronduit (both described separately) arose. New bombproof barracks and depots were created on the bastions and bomb-free buildings for accommodation and ammunition on some ravelins. The courtines and ravelins were also improved. On the bastion of Oud-Molen, a powder magazine with ice cellar (1853), a large bombproof barracks with a hospital (1877-'79) and a bomb-free bakery and butchery (1878) were built near the arsenal. There was also a guard house and a fire spray house (1877) and after 1879 various service houses, including a two-day foreman. home for the bakers, the form. homes for married soldiers (Kooltjesbuurt 3 and 7) and a form. guard house (Kooltjesbuurt 5).
Various military buildings were established at A. Dortsmanplein. The form. Promers barracks (A. Dortsmanplein 3-3a, 1875-'77) is an elongated single layer building covered with earth. The façade in early Neo-Renaissance style features a natural stone portal and rich sculpture with a national coat of arms, a helmeted head, lions and lion masks. This building later became the function of youth club and office, and is now used as a restaurant. Furthermore, there are the form. canteen (A. Dortsmanplein lb, 1880), a white plastered one-layer building with cut wind springs (now V.V.V.-office), and the forem. garrison office (A. Dortsmanplein 5, 1887-'88), a two-storey building with checkered middle and corner ramparts.
In 1895-1906 the envelope (Korte en Lange Bedekteweg) received concrete shelters. In 1915 the Amsterdam gate was demolished and replaced with a denomination. The access was also shifted next to the Utrecht gate (Captain G. A. Meijerweg).
After the removal of the fortification status (1926), the ramparts were quickly protected and dismantling and demolition could be prevented. In the west wall - the courtine between the bastions Nieuw-Molen and Turfpoort - a third entrance was made. It was done by W.M. Dudok with city architect B.T. Deenik developed S-shaped route was established in 1938-'39 as part of a unemployed project. The Dutch Fortress Museum (Westwal 6) has been on the Turfpoort bastion since 1954
established, whose administration is included in the double depot. A restoration of the fortress was carried out from 1964 until the end of the 20th century. To the south-west of the Naarden fortress is an inundation lock constructed in 1787. The two associated lunettes were rebuilt in 1873 to the batteries Karnemelksesloot (Naardermeer approx.) And equipped with earth-covered bombproof buildings. In 1915 two buried concrete shelters were added.
