海蟾宫松花蛋，是修武县五里源乡的传统特产。传说道士刘海蟾，于五里源村北马坊泉，令群鸭取松花蛋酬谢仙女（后人在泉畔筑宫），海蟾宫松花蛋由此得名，其历史悠久。特点是"长存不坏，打开呈固体状，红清黑黄，蛋清透明，并有一朵朵状若松针、晶莹秀丽的松花图案，柔软适中，香气袭人，食之余香绕口。兼有滋肾阴、状元气。祛病去火之功能，为上乘补品。在河南乃至全国享有盛誉。元末以后，历代皇家都视其为皇宫御宴之美味。
    
    海蟾宫松花蛋问世于宋大定二十五（公元1185年）年，距今已有800年历史。当地群众根据石灰可以烧熟鸡蛋的道理，反复实践，终于摸索出制作海蟾宫松花蛋的妙方。每100个鸭蛋，用柏枝、竹叶少许，茴香一钱半，花椒五钱，茶叶一钱半，放在六市斤水中煮沸，将水倒入放有碱面、食盐、生石灰的溶器内，加入四两草木灰和成硬泥，均匀地包蛋上，然后装缸密封，百日即成。
    
    海蟾宫松花蛋之所以能在同类产品中独具一格，享誉全国，除了其精细的加工方法外，马坊泉畔的鸭子长期生活在未受污染的水中，多食"活石头"（灯似瑚珊似的水虫遗骸，状若小石子）和鱼、虾等活食，也是一个重要的原因。
    
    近年来，修武县农科所和各乡镇企业，以及马坊泉畔的十余个村庄，数百户农民，纷纷从事海蟾宫松花蛋的制作，年产50万个，但仍供不应求。全国各地来人来函，索取海蟾宫松花蛋的制作方法，海蟾宫松花蛋已在全国各地安家落户。



    Haichangong Preserved Duck Eggs is a traditional specialty in Wuliyuan, Xiuwu County. It was created in Dasong period of Song Dynasty 800 years ago, when people created this making recipe through trial and error depending on the truth of lime being able to heat eggs to ripe.
      
    In the terms of its characteristics, it can be kept for a long time without getting rotten, has solid red and transparent egg white with needle-liked pictures in it, tastes soft and moderate, smells fragrant, contains medical functions of nourishing females, strengthening males, eliminating diseases and heat, is regarded as a superior tonic. Thus, it enjoys a high reputation in Henan even the whole nation. It has been regarded as a delicious food in imperial feast after Yuan Dynasty.  
      
    Haichangong Preserved Duck Eggs stands out of all the similar products not only thanks to its delicate making technique but also contributes to ducks here are never polluted and mostly eat living stones(water bug remains similar with corals), small fishes and shrimps. In recent years, Haichangong Preserved Duck Eggs has set its position in almost everywhere in our country.