College Walk
College Walk is the pedestrianized stretch of 116th Street on the Morningside Heights campus between Broadway and Amsterdam Avenue.
Originally a busy street, it was swapped for some worthless land the university owned upstate during the tenure of University President Dwight D. Eisenhower.
During the holiday season, the trees along College Walk are lighted, a period which is kicked off by the Tree Lighting Ceremony. The trees remain lit until the end of February.
From Wikipedia's article on Columbia University
With lit trees during winter. From Wikipedia's article on Columbia University