They took Naarden easily. Its defence works were old and poorly maintained. In the 17th century Naarden was a small fortified town overlooking a stretch of dry ground between the sea and the marshes of the river Vecht (the fortifications dated from the 1570s). After Louis XIV of France invaded the Netherlands in 1672 the fortifications were updated to modern standards. Most of the fortifications that exist today date from this period. The fortifications can be separated into two parts: the part facing the sea and the part facing the land.
During the 19th century the fortifications were updated, resulting in the construction of many new bomb shelters and other army-related buildings like barracks. At the end of the 19th century the increased fire power and range of the artillery made the defences at Naarden useless.
As a consequence of the new strategies used in warfare the emphasis of the fortifications went from the inner to the outer circuit - the covered way. In the 1890s a lot of bomb shelters were built here, most of which still exist. This gives a nice visible illustration of the progression in fortification.
After the First World War the need for Naarden as a fortress was over. The army left and it was turned into a monument and preserved just in time to prevent it from being demolished. You can walk around and inside Naarden freely - the covered way makes an excellent walking path to discover the fortifications.
One of the bastions holds a museum about the fortress, which gives a lot of information about the town's history. The museum also gives access to all the tunnels and casemates, making it a must in exploring the fortress.
The landward fortifications consist of arrow-headed bastions'connected by curtain walls, of which the lower sections were made of bricks. The flanks have two levels; the top level is on the top of the bastion and the lower part is just a few metres above the water. The lower part of the flank, which can be reached through a tunnel from the street behind the bastion gives access to 5 casemates'in the faces of the bastions and a powder magazine. From the lower flank a tunnel leads to a small pier, from which the outworks could be supplied by boat. Beyond the last casemate lies the listening tunnel; a long tunnel along the face of the bastion where guards were able to hear the enemy approaching on the water through holes in the roof.
The large bastion holds the arsenal (now a furniture showroom) as well as a sluice gate. This sluice was used to protect the harbour and to enable ships to come into the town from the sea. Two batardeaux'were built across the ditch to connect the sea dam with the town walls. Around the whole town there was a covered way'with a second ditch in front of it. The town had two gates, of which both the originals have been demolished. The Amsterdam gate doesn’t exist anymore and the current Utrecht gate dates from the 19th century. In the 20th century a third entrance into the town was made.References:
The city walls of Avila were built in the 11th century to protect the citizens from the Moors. They have been well maintained throughout the centuries and are now a major tourist attraction as well as a UNESCO World Heritage Site. Visitors can walk around about half of the length of the walls.
The layout of the city is an even quadrilateral with a perimeter of 2,516 m. Its walls, which consist in part of stones already used in earlier constructions, have an average thickness of 3 m. Access to the city is afforded by nine gates of different periods; twin 20 m high towers, linked by a semi-circular arch, flank the oldest ones, Puerta de San Vicente and Puerta del Alcázar.