The otherwise gray canyon that is Madison Avenue begins to finally open up here towards the end of it's run. The relentless skyscrapers finally start pulling their weight with the impressive New York Life Building, not to mention the old Court House (Appellate Division of the Supreme Court), and the Met Life Tower - all three of which are landmarked. The street really opens up after 26th Street when Madison Square Park takes over on the western side of the block.
More than any other park I can think of, MSP has an oasis feel to it. It's just so lush, and the area around it so open, with so many famous buildings surrounding it. With the reconfiguration of 5th Avenue and Broadway on the other side, the park seems to spill out into the street, furthering this image.