complete the 3.5 km Waterfront Promenade around Marina Bay. It includes a new eco-friendly visitor centre and the Helix Bridge linking Bayfront to Marina Centre where the Youth Olympic Park is located. The Promontory @ Marina Bay (formerly Central Promontory Site) will be used as an interim event and public space used for activities such as theatres and carnivals. In 2008, Marina Barrage was built, converting the basin into a freshwater Marina Reservoir. Events at Marina Bay The Formula One Singapore Grand Prix has taken place annually since 2008 (with the exception of the and seasons) on a street circuit adjacent to Marina Bay. Since its construction in 2007, The Float@Marina Bay has hosted events such as the National Day Parade, New Year's Eve Countdown and Singapore Fireworks Celebrations, and also serves as a spectator stand for the Singapore Grand Prix. Furthermore, it also played host to the Opening and Closing Ceremonies of the inaugural 2010 Summer Youth Olympics. The area also hosts the annual i Light Marina Bay, a sustainable light art festival. The event space next to Marina Bay Sands, known as The Lawn, hosted the first overseas and Singapore edition of ArtBox Bangkok on two separate weekends, 14–16 April and 21–23 April 2017. Infrastructure The Singapore government pumped nearly S$2 billion (about US$1.2 billion) to build the infrastructural base for Marina Bay, which includes the Marina Barrage, increased connectivity to the MRT, and the new Marina Promenade and Helix Bridge. Common Services Tunnel The Common Services Tunnel is a development of the Marina Bay area in Singapore. It is said to be the second of its kind in Asia after Japan. This utility tunnel houses telecom cables, power lines, water pipes as well as provision for pneumatic refuse collection pipes. The phase one of the tunnel has cost about S$81 million (about US$51 million) while phase two, cost around S$137 million (about US$86 million). District cooling SP Group's subsidiary, Singapore District Cooling, started operating Singapore’s first district cooling plant, supplying chilled water supplies to One Raffles Quay in May 2006. A second district cooling plant was commissioned in May 2010, which will supply chilled water for the air-conditioning of buildings in the area through pipes housed within the Common Services Tunnel, according to the report. Built at a cost of some S$110 million (about US$69 million), the second district cooling plant will be able to serve 1.25