North/South Gyeongsang-do (East/Southeast Korea) Rock Climbing

The biggest cities in the southeastern part of Korea are Busan, Daegu, and Ulsan. Busan and Daegu have international airports while Ulsan has a regional airport. All have KTX train stations that pass through the city frequently. 

Areas to stay: Seomyeon is considered the heart or "loop" of Busan with the trains all converging there. Great food and night scene. If you're climbing Buchae or Daeryuk, Stay near Dongnae (동래) train station or Geumjung Mountain (금정산). To see a lot of non-Korean folk, head over to Gwanganlli beach and grab a beer at Gorilla Brewery or grab a pizzas at Slice of Life (솔탬하우스). Haeundae beach is one of the busiest and nicest beaches in all of Korea, where Songjeong beach on the southeast side of side is quieter and has a good surf scene. 

Indoor climbing gyms: 

Waverock climbing gym is great, with locations near Busan University, Gwanganlli, and Seomyeon. There is an outdoor artificial climbing wall in Dongnae (type in 동래 인공암벽장 on Naver/Kakao maps).