Lincoln Cathedral, the fourth largest cathedral in England and once the tallest building in the world. It has hosted the English Parliament three times and is the birthplace of the Lincoln Imp, and enduring symbol of the city and the county. It was built in roughly two weeks in January/February in collaboration with fellow UK builder SoleSol06 (if you look closely you can probably tell who built what).
It was built for the Build the Earth project with plans for further expansion of the city already underway.