Construction work has reportedly started on the 5-star Songjiang Hotel, a 'sunken hotel' being created in a 100m-deep water-filled quarry in Songjiang near Shanghai, China.

Situated inside the Shanghai Sheshan National Holiday Resort area, the 21-floor hotel will have two underwater levels, 17 floors between the surface of the water and ground-level and two floors above ground-level. The underwater floors will house a restaurant and guestrooms facing an aquarium, while the lowest level will contain a leisure complex offering a swimming pool and water sports. An extreme sports centre for rock climbing and bungee jumping will be built on the lip of the quarry and accessed by lifts from the hotel.

All the 400 bedrooms will have balconies with views of a waterfall opposite the hotel. Designer Atkins has made sustainability key to the hotel's construction, ranging from using green roofing to generating electricity and heating from the site's geothermal energy. A naturally-lit internal atrium will incorporate the existing rockface of the quarry.

The hotel, for which Atkins won an international design competition in 2006, is expected to be completed by the end of 2010.