Unbuilt

I deem myself lucky that in my childhood, there was always some kind of wilderness to explore. In the Philippines, there was the Martianesque red-soil vastness of Don José Heights in Quezon City. In BC, there were the dirt mounds on the unbuilt school grounds of Rideau Park on Lulu Island. Red poppies grew in the brown earth. It was then the debut of the Star Wars franchise; I imagined Jawas might have lurked in the mounds. There were impromptu mountain bike tracks in the mounds.

Source: tatoeba (12933977)

Yerkes created the GNP&BR [Great Northern, Piccadilly & Brompton Railway] in 1901 by merging two underground railway companies with unbuilt lines - the Great Northern & Strand Railway and the Brompton & Piccadilly Circus Railway.

Source: wiktionary