Gardens by the Bay is a park of a hundred hectares on reclaimed seabed on the waterfront of Singapore, beside Marina Bay, where eighteen steel supertrees between 25 and 50 metres tall are planted with 200 species of climbing plants, linked by a walkway at treetop height and lit every night in a show set to music, beside two glass domes that hold a cool Mediterranean garden and a cloud mountain with a waterfall inside them. The garden was ordered before its ground existed, in an international competition of 2006 for land still being reclaimed from the sea, and it opened in 2012; the supertrees are concrete cores clad in steel and planted with ferns, orchids and bromeliads, and some carry solar cells and the vents of the domes' cooling, while the OCBC Skyway, a walkway of 128 metres, links the two tallest at 22 metres up, with the canopy at eye level and the skyline of the bay beyond. Every evening at dusk the grove lights up in sync with music for a free show, the towers glowing purple, green and gold above the lawn where the crowds gather.
The domes are the other half. The Flower Dome holds olive trees, baobabs and the plants of the Mediterranean and the dry continents in a cool, dry climate under glass, with a field at its centre torn out and replanted several times a year, cherry blossom from mid-March in a manufactured winter and Dutch tulips from late April one degree off the equator; the Cloud Forest dome holds a man-made mountain of 42 metres clothed in moss, orchids and pitcher plants, with a waterfall of 35 metres dropping off its face and a spiral walkway climbing through the mist to the top. The cold inside both domes is made by fire, since the horticultural waste of the city is burned to power the chillers. Gardens by the Bay is a garden built on sea that was not yet land, and the trees in it are made of steel.