From 63rd to 71st Streets, the FDR Drive passes under a series of interconnected at-grade tunnels. The segment from 63rd to 68th Street runs under an annex constructed by Rockefeller University, while the section of roadway between 68th and 71st Streets runs underneath the pilotis of the NewYork–Presbyterian Hospital. Afterward, the FDR Drive continues north at ground level. There is a southbound-only entrance and exit, labeled exit 13, at 71st–73rd Streets, serving Lenox Hill on the Upper East Side. Another southbound-only entrance exists at 79th Street; there is no exit from either direction, nor is there any exit number reserved for this interchange.