The problem of the accessibility of Web pages still remains unattended by many sites, but it is expected to become more important in the near future. If the scope of publishing web pages remains the universal access by everybody, we need that pages be accessible. A page is accessible if it can be viewed by many different browsers, in particular by the special browsers used by disabled people. It is worth noting that accessible pages have an important added value, since they are easily accessed also through PDA or other portable devices. A whole site has been developed that comprises 28 pages, each violating one specific WAI (Web Accessibility Initiative) directive, for a total of 40 checkpoints (or subcheckpoints). This means that with these pages about half of the WAI directives can be checked in the tools. This site constitutes an initial benchmark for the testing of the validation tools. This project still needs some work done, and this paper is also a call for collaboration in order to enlarge and refine the benchmark.