From Chungmuro Station subway to Seoul Express Bus Terminal then bus to Donghae. 3 h 58 min ₩28,536. From City Hall Station subway to Dong Seoul Bus Terminal, bus to Chuncheon, then bus to Donghae. 5 h 41 min ₩24,304. From Seoul drive to Tonghae. 2 h 44 min ₩41,200.