When the old Gyeongui rail line was put underground, the city turned the freed-up track bed into a long, narrow ribbon of park running through Yeonnam-dong. Locals nicknamed it "Yeontral Park," and on warm evenings the lawns fill with students, couples, and picnicking office workers sharing convenience-store beer and fried chicken.
The real draw is what lines the park: the Yeonnam-dong stretch beside it has become one of Seoul's densest clusters of independent cafes, brunch spots, and small restaurants, spilling out of converted houses. Walk the green strip from Hongik University Station and duck into the side streets whenever something catches your eye — this is the gentler, more grown-up side of Hongdae.