Hoenderloo, Netherlands  - Henk Ruseler, a ranger at Hoge Veluwe National Park in the Netherlands, went into raptures at a heathland lake called Deelense Was. "To experience sunset here in the evening, then dusk and the gathering night - these are marvellous moments," he said.

A narrow corduroy road led across the marshy ground to open water, and two wooden benches beckoned visitors to sit awhile.

Situated north-west of the Dutch city of Arnhem in the triangle formed by it, Apeldoorn and Ede, the park, which is fenced in, covers 50 square kilometres and is the second-largest nature reserve in the Netherlands. Its network of trails stretching 42 kilometres can be explored on bicycles which are free to use.

The varied landscape - forests of pine, beech and oak, heathland, lakes and drift sand - was formed during the last ice age. "One hundred and fifty years ago, most of Hoge Veluwe was still covered with extensive sand dunes," noted Jaap Norg, a nature guide in the park.

Afforestation began in the 19th century, however, as pine wood was needed for the mining and paper industries. The forests gradually spread, and the sand dunes and heathland were then in danger of disappearing completely.

"Since 2001, some woodland has been cleared so that more sand dunes can form and the original character of the health and sand landscape can be preserved for the future," Norg said.

Visitors to the park, called "the Netherlands' green lung," can learn much more about it on one of the guided tours. They include a two-hour bike ride, a nature exploration tour on winding forest and heath trails, and an eight-hour "safari" with Ranger Ruseler.

Most of the more than 500,000 people who visit the park each year also stop by the Kroeller Mueller Museum, which has been in the centre of the park since 1938. In 1917, the wealthy industrialists Helene Kroeller-Mueller and her husband, Anton Kroeller, acquired large swaths of what is now the park as hunting grounds.

With her passion for collecting, art connoisseur Kroeller-Mueller laid the foundation for the museum, which now houses the world's second-largest private collection of works by Vincent van Gogh after the Van Gogh family itself. Among them is a famous self-portrait.

The some 90 paintings and 180 drawings also include masterpieces by Pablo Picasso, Auguste Renoir, Claude Monet and Piet Mondrian.

In 1961, a spacious sculpture garden combining contemporary art with nature opened next to the exhibition halls. Containing more than 150 sculptures and installations in an area of 25 hectares, the garden is one of the largest of its kind in Europe.

Among rhododendron and wind-blown pines, works by Auguste Rodin, Henry Moore, Barbara Hepworth, Richard Serra, Jean Dubuffet and Claes Oldenburg can be seen. (dpa)