Freedom from barriers

Our online pages have been specifically designed to make them accessible to as many internet users as possible. In other words: they are barrier-free.

You will find more information about freedom from barriers on the Barrierekompass website, a specialist portal on the subject of barrier-free web design.

Further links

If you are interested in freedom from barriers, the following German links will be of assistance:


Wissem Castle at Troisdorf

Help for using

This Help should explain how you can make full use of this internet site, which has been designed to be barrier-free, and derive maximum benefit from the advantages of improved accessibility.

Brotkrümelpfad, breadcrumb trail or Ariadne thread

Our breadcrumb trail is located below our social networks section and starts with the words "You are here". This breadcrumb navigation is designed to help you find your way around our website. All the links, which show the location of the document that has just been displayed, are strung together as a trail in the overall structure of the website. The homepage is always the starting point. You can thus move back to the homepage with the help of the links from the document.

Enlarge function on Mozilla, IE and Opera

Graphic browsers such as Mozilla Firefox, Internet Explorer and Opera have excellent enlarge functions for people with impaired vision.

Screenshot which shows how to change the settings in the Opera browser

Opera in particular has a unique zoom function. The browser can be used to magnify the displayed contents by up to 1000 per cent. Special feature: Not only the text, but all elements, such as graphics and pictures, can be enlarged. Choose View from the menu bar and set the zoom factor.

If you would like to avoid using the Opera menu, there are various ways of controlling the zoom factor via your keyboard. It is possible to enlarge the display by increments of ten per cent by pressing +, or to reduce the level of zoom, likewise in units of ten per cent, by pressing -. You can return to the normal view by pressing 6. Newer versions of Opera can also be enlarged in increments of 100% by using CTRL + +, or reduced by using CTRL + -. We must mention the possibility of switching between author and user mode in Opera. Numerous preset view options, from high contrast to the view for small screens, enable virtually all users to set their preferred options.


Mozilla Firefox
Screenshot which shows hoe to change the settings in the Firefox browser

If you use Mozilla Firefox, an excellent enlarge function is also available to you. This also covers graphics and pictures from Version 3 onwards. You can, however, disable this function and just have the text enlarged. Version 4 onwards also offers the option to drag a button next to the forward/back buttons on the browser via Settings > Toolbar. Alternatively you can access the following settings by pressing ALT + A.

To do this, use the browser menu bar to select View and set the size of the font in per cent. It is easier to use the menu commands CTRL + + to enlarge and CTRL + - to reduce the size of the type. Use the command CTRL + 0 to return the font size back to the default value of 100 per cent.

Internet Explorer

 In Internet Explorer you can also enlarge the size of the font used on this site. To do this, use the browser menu bar to select View and set the size of the font by using font size. In IE you can unfortunately only choose between five levels, from very small to very large.

Anyone who finds this enlargement to be insufficient must go further into his operating system and change the settings in the help function in the system control. You can change the contrasts here, if required. Windows offers numerous presettings as standard. Proceed as follows here:

  • Go to Start > System control or Start > Settings > System control.
  • Open Help function.
  • Select Display.
  • Activate the control box Activate contrast.
  • Under Settings select the contrast of your choice.
  • Confirm the changes.

In Internet Explorer there is a zoom function from Version 7 onwards. This can be used to enlarge or reduce the view of a website. All the contents of the site are adjusted: Text and pictures. It can be adjusted from 10% to 1000%.

This is how to use the mouse:

  • If you are using a mouse with a scroll button (also called a mouse wheel), keep the CTRL button pressed and move the scroll wheel. In this way you can enlarge or reduce the view.

This is how to use the keyboard:

  • You can use the keyboard to change the enlargement level in 10% increments. To enlarge, press CTRL and +. To reduce, press CTRL and -. Press CTRL and 0, to use the 100% level again.

This is how to use the "change zoom level" button:

  • On the bottom right of the Internet Explorer screen is the "Change zoom level" button.  Click on the arrow to the right of the button.
  • You may now use the specified zoom level. Click on the required percentage to do this.
  • You can also set the level of zoom yourself. To do this, click on User defined. You can now enter an enlargement value into Zoom in %. Then click on OK.
  • If you simply click on the Change zoom level button, you can switch quickly between 100%, 125% and 150%.
Other output devices/resources

You can find other resources for the above browsers, such as a screen magnifier or a screen reader, in the list of resources on Barrierekompass.

Help with file formats

Information cannot always be shown in HTML format. Additional file formats are required for forms, multimedia and downloads of large files. Here you can find out how to open individual types of files and what to look out for when doing so.

PDF files

PDF files enable forms and other documents to be viewed and printed on virtually all operating systems.

It is not straightforward to provide PDF files barrier-free. We do not always manage to do so. This applies mainly to files made available to us by third parties.

You can find detailed information on this subject on the website Einfach für alle or in the free handbook for barrier-free PDF.

To be able to open a PDF file, you need the free Acrobat Reader program by Adobe. If Acrobat Reader is already installed, you can view PDF documents by selecting the appropriate link.

Division of content and design

Contents are generally separate from the design of the packaging. The same applies to websites. With the help of Cascading Style Sheets it is possible to separate the content of a site from its appearance. A site can thus have several different versions without changes to the code or be implemented for different output media (e.g. print). The individual areas of the site, i.e. its navigation, headings and passages of text, have been produced manually with the help of valid and standard XHTML. A valid code is the basis of freedom from barriers and ensures that an online presence is sustainable. Due care has been taken when producing the site to ensure fast responses and pleasant reading.

Working with JavaScript

The town of Troisdorf uses JavaScript in individual areas of this website. This includes individual functions, such as the availability of a print function on each page. We have taken care to ensure that user-friendliness is enhanced when JavaScript is on. When JavaScript is off, however, contents and key functions are not available to you. Not only does this help to ensure freedom from barriers, it also enhances security.

Browsers and recommendations

 Even older browsers which do not, or no longer, meet current standards can access our web pages. All contents and functions are fully accessible, although the design may be different. For even better results, more security and more convenience when surfing the net, we recommend that you use modern browsers, such as the current version of Mozilla Firefox, which is available on the internet free of charge and available to download for most operating systems.

Certificates and standards

The pages at have been designed in accordance with valid internet standards. The following standards have been duly heeded and observed wherever possible:


All contents have been implemented in accordance with W3C guidelines for Web Content Accessibility.

Valid CSS

Only valid CSS has been used for the implementation. Try us out.

Valid HTML code

Validate our site yourself.