Daejeon is South Korea's fifth-largest metropolis, with a population of 1.5 million as of 2019. Located in a central lowland valley between the Sobaek Mountains and the Geum River, the city is known both as a technology and research center, and for its close relationship with the natural environment. Daejeon serves as a hub of transportation for major rail and road routes, and is approximately 50 minutes from the capital, Seoul, by KTX or SRT high speed rail.