Llewelyn Davies Yeang has won its first major international design competition since the practice launched last year. The architecture, planning and design consultancy will masterplan a 2km-long "ecological corridor" for Istanbul, Turkey, on a site that has been dominated by unplanned development.

Ken Yeang, who will lead the project, said: "We looked at the ecology of the locality and found that in the last 20-50 years urbanisation had crept northward, devastating the ecosystem. We are creating an eco-corridor to make the ecosystem whole again."

The eco-corridor, complete with bridges, will link the mountains and uplands in the north with the coastal region in the south. Yeang described the corridor as "weaving across the site, a single nexus of vegetated area, not just at ground level but over canal, under highways."

The site will also become a giant urban park with a dolphinarium, national cultural centre, ecology biodomes, residential and leisure facilities, a 1,000-berth marina and two hotels. It will take nine years to complete.

Yeang said he would not have got the level of expertise at LWY had he been in Malaysia, and he was "deliriously happy" to win.