The stone mullions surrounding this visitor centre by Irish firm Heneghan Peng Architects imitate the towering basalt columns of the volcanically formed Giant's Causeway (+ slideshow).

Created around 60 million years ago by the movement of basalt lava, the causeway is the most popular tourist attraction in Northern Ireland and comprises over 40,000 columns that step down from the foot of the cliff into the sea.

Heneghan Peng Architects won a competition in 2005 to design a visitor centre for the Giant's Causeway, providing exhibition spaces, a cafe, toilets and a giftshop.

The new building opened this summer and is described by the architects as "two folds into the landscape". The first fold rises up from the ground to create a building with a sloping grass roof, while the second angles down to form a car park and entrance that meets the level of the approaching road.

"It is a carefully sculpted intervention," say the architects. "It is both visible and invisible; invisible from the cliffside yet recognisable from the land side."

Between each of the stone mullions, vertical windows line the walls and surround a cafe that overlooks the coastline from the far end of the building.

Visitors can climb up over the grassy roof, where skylights let them peer down into the exhibition spaces.

Floors inside the building are staggered to negotiate the sloping site, but ramps connect each level.

Other projects at natural landmarks include the installations along the Norwegian national tourist routes.

Photography is by Hufton + Crow.

Here's a project description from Heneghan Peng Architects:

The project is located at the ridgeline of the North Antrim coast at the gateway to the UNESCO World Heritage Site.

The proposal for the new visitor facilities can be understood as two folds into the landscape. One folds upwards revealing the building and the second folds down to form the carpark and shield it from view of the approach road and coastal path. Between the two folds, a ramp leads to the coastal ridgeline which is restored at this location.

The visitor’s centre at the Giant’s Causeway is experienced as an event along the route to the Causeway and the coastline. It is a carefully sculpted intervention into this landscape which is both visible and invisible, invisible from the cliffside yet recognisable from the land side.

Internally the building can be understood as a series of stepping floor plates which are linked by a series of ramps.

These floor plates allow the different activities of the building to flow into each other creating a fluid movement through the building for the visitor.

The cafe has been situated close to the main building entrance with a long view to the coastline. The visitor ends the route through the building by exiting onto the access road to the stones.

The folds are precise and geometric yet vanish into the patchwork that forms the tapestries of fields.

The architectural expression of the edges of the folds is singular, stone mullions that echo the columnar landscape of the Causeway site.

The strategy for the building creates a space between the basalt and the folded plane of the grass roof; a space formed within the materials of the site.

The basalt edge is formed as a weave between basalt stone columns and glazing where changes are created in transparency and opacity along the visitor’s route.

What belies this simple façade concept is a carefully engineered solution which evolved around the inherent properties of the locally sourced basalt stone.

The aspirations for this project in every way are of the highest order as befits its location, excellence in architectural and landscape design, excellence in sustainable practices and construction.

The project’s design has received a BREEAM “Excellent” rating.

Client: National Trust
Gross Internal Area: 1800m2
Location: Northern Ireland

Architecture, Landscape Concept and Interiors: heneghan peng architects
Competition: Shih-Fu Peng, Róisín Heneghan (Project Directors) Chris Hillyard, Aideen Lowery, Marcel Piethan
Project Design & Construction Stages: Shih-Fu Peng, Róisín Heneghan (Project Directors), Julia Loughnane (Project Architect), Monika Arczynska, Jorge Taravillo Canete, Chris Hillyard, Kathrin Klaus, Carmel Murray, Padhraic Moneley, Catherine Opdebeeck, Helena del Rio.

Structures: Arup
Building Services: Bennett Robertson
Quantity Surveyor/Project Manager: Edmond Shipway

Facade Engineering: Dewhurst MacFarlane
Planning: Turley Associates
Civils: White Young Green

Landscape: heneghan peng architects (Concept design) Mitchell + Associates (Implementation)
Exhibition Design: Event
Accessibility: Buro Happold
Acoustics: FR Mark

BREEAM: SDS Energy
Fire/Traffic/Environmental: Arup
Specialist Lighting: Bartenbach Lichtlabor
Specification: Davis Langdon
CDM Coordinator: The FCM Partnership

Above: Hexagonal basalts at the Giant's Causeway

Competition: 2005
Appointment: 2006
Start On-Site: November 2010
Completion: May 2012
Open to public: July 2, 2012
Contractor: Gilbert-Ash
Contract: NEC 3 Option A

Site plan - click above for larger image

Ground floor plan - click above for larger image

Longitudinal section - click above for larger image

Cross section - click above for larger image

East elevation - click above for larger image

South-east elevation - click above for larger image

South elevation - click above for larger image