Tangshan Quarry Park, 20 km away from downtown Nanjing, was formerly a quarry site with several remaining pits of Longquan Quarry in Jiangning County. The quarry site, abandoned for many years, has become a "scar" in the city. In 2017, as response to the pilot program of "City Betterment and Ecological Restoration", Tangshan launched the ecological restoration and functional replacement project to improve the environment of the quarry site and create a quarry park for tourists.

In the wetland area at the main entrance to the park, three building clusters are planned around a reserved pond for the purpose of way-finding, relaxation and dinning of tourists. On the west of the pond stands the tourist center to connect the main entrance square. Across the water on the relatively quiet east side of the pond is a tea house, which is connected to the tourist center via a walkway over water. On the north of the pond is the restaurant, sitting on a small hill built with quarry refuse. The hill, with a height difference of 15 m, is densely surrounded with some wild trees.

Many architects are interested in designing a small building at a relative vantage position of a natural site. They respond with different design solutions, such as Botta's mountaintop chapel with a self-sustained system, and Zumthor's waterdrop-shaped chapel in a concise style, but some choose to dissolve and completely permeate the building volume into the environment, such as Tadao Ando's Chichu Art Museum. Different solutions reflect architects' different way of thinking and expression of the natural environment.

Recognizability
Our goal is to create a highly recognizable image within a natural setting, making the park location visible even from a long distance and diverting visitors' attention from the exposed rocks of the quarry site to the buildings. The hilltop building creates a visual focus at the main entrance as result of the height difference and establishes a relationship of "seeing" and "being seen" with the other two building clusters. This resembles the way to locate "pavilions" in classical Chinese gardens. In the Summer Palace, an imperial garden, "Pavilion of the Buddhist Incense”, is place on the main axis. Though it is built on the hillside of Longivity Hill, its top is higher than that of the hill, making it the central building dominating the garden not only in height but also in volume. In the Humble Administrator's Garden, a private garden with a relatively free layout, the "Floating Green Pavilion", though placed at the northwest corner, still dominates the entire garden as it reaches the highest level standing on top of an artificial hill. Likewise, our preliminary intention is to create an iconic image on top of the hill at the park entrance to make the site highly recognizable.

Way-finding
As response to the poor way-finding at site, we studied the relative locations between the site and the city, and between the buildings when we started to work on the building layout. The gigantic quarry pit and the relatively low urban space in Tangshan Resort forms a sharp contrast, which offers a landscape setting where the quarry pit serves as the backdrop while the buildings as the exhibits, and tourists in the park as audiences. This offers the first clue for our layout design. In the spatial design of the park entrance, although the three building clusters and the lakes are relatively free-flowing in layout, their triangular spatial pattern and height difference, in fact, also indicate a certain sense of orientation. By doing so, we intend to echo the inherent axis of the site, make clear the spatial relations and identify the heart of the site.

Building volume
Functionally, the restaurant is not complicated. According to its intended uses, three building volumes are envisioned respectively for the BOH area, the dining area and the viewing tower, so as to achieve appropriate building scale. The BOH area is on the ground floor, where the quarry sludge without sufficient bearing capacity has been replaced with a concrete platform to serve as the kitchen, and the equipment and management areas of the restaurant. The viewing tower, which also serves as the building's transportation hub and the kitchen's fume shaft spine, defines the spatial node of the park, and provides visitors a way-finding focal point and a place to enjoy the attractive views at a height. The dining area is the core functional space of the building, the space for dining and sightseeing. It is designed into a U-shape corridor to enhance the orientation of the space. Meanwhile, the U-shape space also maximizes the view and defines the tour route for tourists.

Sense of dynamic
Instead of a relatively stable relationship between site and building volume, we seek to inject some dynamic into the facility following the topography of the hill. To do so, the main building is slightly tilted forward and the U-shape corridor is pushed outwardly to form a huge cantilevered space, intentionally bringing out a sense of weightlessness and motion. Meanwhile, the platform on ground floor is pulled towards the opposite direction, which, together with the physical connection with the high tower, balances the dynamic and stability in structure and realizes a highly energetic project site.

Access
Visually, the access to building provides a major means for people to experience the building. Subject to the master planning of the park, tourists arriving by car may slowly approach the building from the western road, while pedestrians can access the building via more diversified paths. They may start from the tourist center, walk through the island on water, go past the tea house, and then follow the zigzag path up the hill to reach the entrance square of the restaurant. The Mining Park on the northeast offers alternative access to the restaurant. People may experience fun climbing, riding slides and other amusement facilities in the amusement area before walking to the restaurant. A gabion wall between the amusement area and the front square of the restaurant separates the noisy space from the quite one, serving as the sign and boundary of the square. One may ascend the stairs along the gabion wall and pass a slightly arched bridge before approaching the main spatial axis of the project.

Aerial view and distance view
For this F&B facility within a park setting, we intend to maximize its public nature, so that it can be open to more people and serve as a public resting and viewing platform instead of a mere dining space. To this end, we plan a platform overhanging along the U-shape corridor. Though this might kind of affect the experience of the dining space, it does offer a valuable tour path for the general public and makes the restaurant no longer the dead end of the tour routes. Without entering the building, people can tour around the building from the main entrance and overlook the park on the 15m-high platform 300m away from the park entrance. The roof of the restaurant and the top floor of the tower are relatively open, offering ideal places for tourists to enjoy a distant view of the city.

Structure and material
Two structural systems are adopted for the building. The BOH area and the viewing tower”, as the major overturning-resisting components, employ the reinforced concrete beam and column system. The U-shape corridor uses the steel truss structural system without web members to allow for more views of the 20m overhanging space. For materials, consistent building materials are used for interior and exterior interfaces, creating an integral experience of interior and exterior spaces. Anodic aluminum oxide panels are clad on suspended ceiling of the restaurant, the same as those on the curtain wall of the building. Anti-aging terrazzo is used for outdoor platform and the interior floor, while curved ultra-white toughened glass is used for the interior and exterior interfaces. Floodlighting of the building is designed in view of the general lighting design of the park. As the Level I illumination area and the key night lighting display interface of the park, the building features warm-colored rippling light projected onto the bottom of the cantilevered U-shape corridor and the overhanging eaves, highlighting the sense of dynamic and enhancing the recognizability for the night view of the park.

Summary
As a service facility of moderate size in Tangshan Quarry Park, the restaurant at a special geographical location is endowed with more urban attributes. We envision it not merely a spatial node in the park and landscape for tourist resting, but also part of the cityscape. Together with the gigantic quarry pits, it awakes people's memories about the places of Tangshan area.