<Li> Im Won - hee as a doctor (ep. 19) </Li> <Li> Kim Seul - gi as a mermaid (ep. 20) </Li> <P> Filming began on August 19, 2016 in Goesan, North Chungcheong Province, South Korea . The production team then flew to Palau to film underwater scenes . The cast and crew flew to Spain on September 11 where they filmed in A Coruña, Ribadeo, Lugo, Tossa de Mar and Castell de Santa Florentina in Canet de Mar, as well as Begur (Es Cau Swimming Pool), Sitges (Town Hall and other backdrops) and Barcelona (exteriors of Palau de la Música Catalana, etc .), among other places in Catalonia and Galicia (Spain). The first script reading was held on October 8, 2016, two months after production began, due to the busy schedules of the actors . It lasted three hours and covered the first four episodes . </P> <P> This drama served as a reunion for both Lee Ji - hoon and Shin Hye - sun who debuted together in the 2012 KBS2 hit school drama School 2013 as well as Jun Ji - hyun and Hong Jin - kyung who previously worked together in the 2013 SBS hit drama My Love from the Star . </P>

Where did they shoot legend of the blue sea
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