The altar is not worth visiting except for one day in April (which varies with the lunar calendar) : the re-enactment of the ceremony when Joseon kings came here to pray for a good harvest. A royal procession heads to the altar, where food offerings are laid out in special brass containers. Musicians in red robes play traditional instruments, and after the Confucian ceremony the onlookers tuck into seolleongtang (beef soup) and makgeolli (fermented rice wine) free of charge, just as in Joseon days. From the subway exit, walk straight as far as the notice board and turn right. When you come to a fork, go right. The altar is a 300m walk on the right.
