Olle trail 10 course

Alddreu Airfield also known as Cheju-do No. 2 (K-40) Air Base was a former Imperial Japanese Navy Air Service and United States Air Force (USAF) air base on southern Jeju Island. It was mostly returned to farm land from the late 1960s onwards, though the site is still owned and used to some extent by the Republic of Korea Air Force, in particular a grass airstrip known semi-officially as Alddreu Airport.

Mt. Songak is a simple volcano on Jeju Island which has double craters and a parasitic volcano. Crater 1 is about 500 m in diameter, 1.7 km in circumference. Crater 2, the mouth of the volcano in Crater 1, is about 400 m in diameter, 69 m in depth and leans vertically.From Sanyisu-dong to the summit and ridge of Mt.