Columbia University. 2960 Broadway corner of 116th Street, (visitor center: 213, Low Memorial Library Mon-Fri 9am-5pm). Tel 212-854-1754. This private university, one of the oldest in the city, is among the best in the world, especially in the field of medical and scientific research. The campus was built in 1897, and today thousands of students annually passing through their classrooms. From here have come 49 Nobel laureates, a figure which not all universities can claim. The esplanade of the c