060 The Forest Tower.

THE FOREST TOWER

LOCATION

SCHOVENHORST ESTATE,

PUTTEN, THE NETHERLANDS

ARCHITECT

SEARCH BV

WRITER

ROB GREGORY

PHOTOGRAPHY

JEROEN MUSCH

Known for its diverse wooded landscape, the Schovenhorst Estate, 50km east of Amsterdam, was founded in 1848. Collecting seeds from around the world, the founding arborists began with an experiment to ascertain which species would grow on the heathland near Putten. The land proved extremely fertile and hospitable, and today the results have yielded four distinct collections; the small and large Pinetum, the Arboretum and the Three Continents Forest. To aid appreciation and interpretation of this spectacle, a new structure called The Forest Tower has recently been added.

'The tower is designed as a condensed path,' says the architect, Amsterdam's SeARCH by, 'rather than a vertical ascension.' Unlike Marks Barfield's Treetop Walkway at Kew Gardens in London (AR November 2008), which offers visitors a horizontal experience of the tree canopies, the route up The Forest Tower is just as instructive and interesting as the destination itself. In fact, there is no singular destination per se. Instead, two cantilevered staircases and two stumpy 'branches' provide distraction and activity en route, and to cap it all, a copse of trees has been planted on the uppermost circular viewing platform, providing a tufty hair-like crop that compensates for space lost on the forest floor and provides an appropriately natural material atop the steel structure.

Climbing up on foot, the first incident occurs at 8.3m above ground (equivalent to being on the roof of a three-storey structure), where a helter-skelter-like stepped ramp performs a 270[degrees] anticlockwise leap. Walking on large-gauge perforated and galvanised steel plate, contained within painted steel balustrades, visitors are gently introduced to the notion of leaving the relative safety of the 4.5m x 4.5m steel core, here being projected off axis by 6.5m. As the ascent continues, the level of exposure and excitement increases and, at the next level, 12m above ground, a viewing (man) box projects by 7.5m, clad externally with smaller (bird) boxes, each with an internal spyhole for curious humans.

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At 18.6m, the stair performs a 9.2m cantilever which causes the stairwell to appear far more precarious to those on the descent. This supports a 22.4m-high half-landing that prepares climbers for the adrenalin crescendo above, where a scramble net has been slung beneath the ramped viewing deck, giving the adventurous an opportunity to roll about or make like a bird, 27m in the air. From the penultimate inclined viewing deck (intended to act as a place for group performance) visitors can, depending on their preference, press noses against the plate glass screen that constitutes the tower's furthest reach of 11m, or lie back and gaze at the reflective underbelly of the uppermost deck; a mirrored convex surface that provides spectacular optical effects.

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A moment of calm presides over all of these various gymnastics when visitors finally reach the elevated copse. They arrive at a new piece of forest/secret garden that also provides the estate with an elevated planting laboratory, where arboricultural investigation is set to continue with a series of experiments into conifer growth, 10 storeys in the air.

ARCHITECT

SeARCH by, Amsterdam, the Netherlands

CONSTRUCTION ENGINEER

Pieters Bouwtechniek

Haarlem