A brownfield on the outskirts of Nanjing was restored by convening a garden exposition and thereafter is transforming into a tourist resort. The project is located in a large quarry of the brownfield and is planned to be a tourist complex themed by regenerated quarries, which includes a hotel, botanical garden, restaurant, café and outdoor theater. The project faced challenges not only from the severely damaged natural environment of the quarry, but also from the complexity of the project's functions and goals. The proposal adopts differentiated restoration approaches in consideration of the geological conditions and landscape characteristics of different parts of the quarry, creating a new landscape while retaining the memory of the site's history. On the basis of researching conditions onsite like sunlight, ventilation and drainage, the design team chose more than 800 species of plants to form 12 thematic plant areas, which showcases the eco-restoration possibility and plant diversity and provides an opportunity of natural education for the public. It also provides a variety of complex functions to transform a negatively barren quarry pit into a vibrant tourist resort complex, creating high ecological, economic and social value.
The Tangshan area, provided with its natural premium hot springs, was a royal spa 1,500 years ago. Today, it remains a resort on the outskirts of Nanjing today due to its monuments, hot springs and good natural environment. Nevertheless, in the 1960s, some limestone hills in the northern part of the region were mined as raw material for cement, as a result plenty of cement plants were built at the foot of the hills. By 2018, the Nanjing government decided to close these quarries and cement plants and transform this brownfield into a tourist resort by restoring the natural environment, regenerating industrial facilities,building comfortable tourist facilities and hosting the garden exposition.
The site that lies on a hillside within the planned garden expo used to be the largest quarry in Nanjing, 1,100m long and 10-22m deep, with two levels, covering a total area of 25.5 hectares.
The client hoped Future Garden to be more than just a show place meeting the needs of exhibition, but also to own lasting charm and the possibility of commercial operation, becoming an attractive tourist destination after the expo. It was therefore planned as a tourism complex themed by regenerated quarries, which includes hotel, botanical garden, restaurant, café and outdoor theater.
The project faced with challenges not only from the severely damaged natural environment of the quarry, but also from the complexity of project's functions and goals. To the east of the quarry is a hotel, and adjacent to the hotel lies a grand outdoor theater hosting stage performances and light shows at night with cliff as a backdrop. The bottom of the quarry is planned as a space for ornamental plants and beautiful fish. Several viewing platforms are arranged on the northern edge of the pit towards the main area of the expo and the interior of the quarry respectively. A series of steps, ramps and escalators connect different levels inside and outside. The proposal aims to restore the quarry and create a characteristic landscape that would become an attraction of the resort area on the one hand. On the other, it is to meet the complex requirements of the buildings for fire fighting, flow gathering and circulation and equipment installation, meanwhile to integrate different types of buildings in the landscape.
As the core of the project, botanical garden is located on the west side of the bottom quarry, with a set of 2-story commercial buildings adjacent to cliff, functioning as café, restaurant, and exhibition. To create a dreamy atmosphere, architects designed the roof of the botanical garden as a giant transparent pool, supported by 42 tall stainless steel tree-like structural columns, with sunlight pouring in through the water and the transparent roof to irradiate a vibrant green world.
The botanical garden is classified as three different habitat zones from west to east namely, arid area, mesic area and humid area through the analysis of sunlight conditions, moisture conditions and earthing feasibility.
As the main entrance of botanical garden, arid garden lies on rocky slope with good sunlight conditions. A height difference of 8m requires steps and ramps to be provided. The rocky terraces combine 67 steps and an 86m-long zigzag ramp, on which various drought- and barren-tolerant plants grow.
The mesic garden is proposed to create rich spatial variations by shaping undulating landform, deep ravines and steep rocks, offering the suitable environment for different plants to grow. In the complex topography there are several thematic plant display areas, such as areas separately for medicinal plants, aromatic and nectariferous plant, relict plant, tea plants, fantastic plants and plants with different colors. To increase the variety and attraction, 2 small green houses are designed to provide shelter for desert plants and aerophytes that cannot tolerate the winter outdoor. A winding skywalk connects the second floor of commercial building to the rockery and viewing platform in the garden, providing a unique experience of traversing through treetops and overlooking the garden scenery.
With low-lying position, humid garden has poor sunlight condition, rainwater and water seepage from the rock flow down along the terrain. The garden consists of two parts: the glistening pond with a winding bridge through the lush aquatic flora; and the sunken space as shady plant area, with terraces and a zigzag ramp leading visitors to the lowest part of the garden. There is a narrow stone canal by the side of terraces and ramp, the texture of canal bottom causes small splashes and gurgles of water. The canal runs along or across the ramp, and dives into the flowers. At the edge of the terraces, water drops from the stone troughs into small ponds, presenting small shimmering cascades and leaving pleasant sound, and then continues to flow along the lower canal, eventually joining the lowest pond. On each level of the terrace and on the edge of the ramp are grown many hygrophilous and shady plants. The canals, cascades and ponds not only produce rich landscape, but also increase the humidity and create better conditions for plants.
A micro-device called "plant bubble" is designed to provide protection for some non-hardy plants, and to display small plants individually. It can be used as a planting bed for teenagers to carry out planting DIY, offering possibilities for future public education and commercial operation.
Located on the east side of the botanical garden, the fish pond is a series of circular ponds above ground level, surrounded by cherries and a continuous boardwalk. This is a place to appreciate colorful carps.
The Misty Garden stands at the middle level of the quarry, 10m higher than the botanical garden. To preserve the memory of the site and differentiate it from the botanical garden on the ground floor, restoration method is only partially used in a series of scattered island-like areas and leave the existing gravel on the surface of the quarry site in the rest of the area. To the west of the Misty Garden is the main entrance to the Future Garden. Flanked by the steep cliff of the quarry, the islands are planted with tall pine trees and understory shrubs, providing the image of a canyon forest, offering a transition space between the quarry and the peripheral forest. The planting presents lower and more sparse when coming closer to the central quarry. The central and eastern planting islands of the garden simulate pioneer plant communities with pine trees, wild scrub and herbaceous plants. A steel boardwalk traverses the gravel beach and planting islands, with several viewing platforms on the edge of the cliff overlooking the underwater botanical garden and fish pond area.
The Cherry Alley lies on the edge of the quarry, with the hillside to the north and the cliff to the south. Considering both safety and landscape effect, cherries are planted on cliff edge in fixed Corten steel planting boxes to form a cherry blossom walkway. The roof of the theater meets Cherry Alley, and small arbors, shrubs, perennial flowers and ornamental grass are planted in the planting boxes, providing a relaxing garden space. A winding walking path along the hillside connects to the viewing platform towards the main area of expo. The roof of the viewing platform is designed with planting beds and seats to provide visitors with a place to rest and enjoy the landscape from afar.
As the most representative landscape of the quarry, the south side of the cliff is preserved, which is over 130 meters high, partly to act as a natural backdrop for performance and a screen for light show, and partly to increase vitality and set off the enormousness of the cliff by planting pine trees and climbing plants on earthed terraces.
The proposal adopts differentiated approaches as non-intervention, semi-restoration and full restoration considering different geological conditions and landscape characteristics in the quarry, and utilizes the abandoned stones as materials for landscape construction, creating a new landscape while retaining site’s memory. The team investigated and analyzed the sunlight and water permeability onsite and worked with relevant institutions to conduct light transmittance tests on the transparent roof, and digital simulations of wind environment underneath to obtain accurate data and calculation results. Accordingly, plant species were reasonably selected to ensure their healthy growth.
The Future Garden showcases more than 800 species of plants and 12 thematic plant areas while preserving the characteristics of the existing quarry, has now become a model of ecological restoration by transforming an abandoned quarry site to a garden of plant diversity, meanwhile provides numerous opportunities for public nature education. The proposal reinvented the barren quarry as a vibrant tourist resort complex offering a variety of functions and creating high ecological, economic and social value. It restores the nature once destroyed by human activities and showcases a future scenario in which man and nature coexist in peace.