There are many attractive places on earth and UNESCO, the most important guardian of culture in the world, has chosen 890 locations, which should be kept for posterity for their ‘irreplaceable importance'. Holland is one of 148 countries involved and can be proud of its nine 'unique and exceptional locations'. Seven of these are scattered across the Netherlands, but two are located within the municipality of Amsterdam. In 1996 the 135km-long Defensive Line of Amsterdam was established as a 'location of extraordinary importance'. Its 42 fortresses were constructed between 1883 and 1920. More recently another incredible attraction was added to this impressive list which also includes such sights as the Great Wall of China and the Grand Canyon. Amsterdam's Grachtengordel, or canal belt, has also been placed on this prestigious list of important world heritage sites. It may also interest you to know that despite all of its waterways, only the Amstel and IJ rivers are natural and not man-made.