Bergen op Zoom has 303 national monuments and 472 municipal monuments and boasts the oldest city palace in the Netherlands (the Markiezenhof, dating from 1485).
The municipality has two nationally protected townscapes: 'Nationally Protected Townscape Bergen op Zoom' and its expansion. [Source: Monumenten.nl]

The Waterschans, dating from 1584, is the city’s oldest fortification. The Markiezenhof, built in 1485, is the oldest city palace in the Netherlands and thus the oldest preserved civic monument in Bergen op Zoom.

For a first visit of one day, combine the Markiezenhof (museum), climbing the Peperbus and a walk along the fortifications via the Ravelijn and the Gevangenpoort. These four are within a 15-minute walk of the Grote Markt.
There are several ways to explore the city centre. The Tourist Information Office (located in the Markiezenhof) offers a number of walking routes on paper. You can get a guided walking tour or the digital version of a walk to follow on your phone. 

Yes. Fort de Roovere and the Moses Bridge are freely accessible. Parking is available at the designated car park in Halsteren, after which you can reach the fort via a walking path. Climbing the associated Pompejus Tower is also free.

Yes. The Hidden Fortress en The Grebbe are two underground monuments that you can visit with a guide. The Archaeology Tour of Stichting In den Scherminckel Foundation departs every first Saturday of the month from the ArcheoHotSpot.

During Open Monument Day (second weekend of September) and the National Heritage Weekend for Defence (third weekend of April), monuments that are normally closed also open their doors. For a peaceful visit, weekday mornings in spring and autumn are ideal. 

In short, there are many opportunities to visit monuments.

When they are open, this is usually indicated by a sign.

Meer informatie with the city guides.