A visitor centre designed by Trace Architecture Office for a park in Rongcheng, China, is a long and thin concrete bridge complete with a lighthouse-like viewing tower clad in wooden shingles.

Called Bridge House, the centre is located to the north-east of Swan Lake Park, Shandong Province, where it faces out onto the wetland landscape and backs onto a dense pine forest.

Swan Lake Park is popular with tourists, who come to watch swans migrating north in October. The local government decided to provide more facilities such as a cafe, toilets and viewing areas for visitors.

Beijing-based practice Trace Architecture Office (TAO) designed the visitor centre to minimise the building's impact on the park while still providing panoramic views.

The concrete structure was cast in-situ using pinewood formwork, bringing a texture to the interiors that helps to introduce some warmth and also responds to the nearby forest.

The simple concrete 71-metre-long structure sandwiches visitor services between two long viewing galleries, spanning soft soil and water.

"It acts like a ruler that extends itself from the wetland to hover over the water pond, through its straightness delineating the sectional change of the landscape below," said the practice.

Circulation for Bridge House has been pushed to its outer edges, where two corridors become areas to view both the wetland and the forest.

"The two sides are semi-open corridors with different atmospheres – the east corridor near the pine forest is introverted and quiet while the west corridor facing the wetland is extroverted and open," they added.

Between these corridors, the southern end of the structure houses the cafe, with a glazed skin that allows it to be used year-round.

To the north, a central toilet block is also surrounded by a viewing corridor, and in the centre of the plan stairs lead up to a simple roof terrace.

A small path leads from the centre to the nearby viewing tower, which stands at 15.6 metres tall and resembles a lighthouse.

Contrasting the heavy concrete of the bridge, the tower is built from wood and steel, with a spiral staircase providing access to the top where a skylight illuminates the whole structure.

Trace Architecture Office was founded by Hua Li in 2009. Recent projects by the practice include a coffee processing facility and hotel and the conversion of a vast Beijing warehouse into an office and exhibition space.

Photography is by Chen Hao unless otherwise stated.