Mt Geumjeong Fortress

On the peak of Mount Geumjeong (Geumjung) in Busan, Geumjeongsanseong was once the largest fortress in Korea. Thought to have been originally built in the Three Kingdoms Period (57 BC - 668 AD), when the Goguryeo, Baekje, and Silla dynasties were at war with each other, the fortress you’ll see today was actually built in 1703 as protection against further Japanese invasions.
Destroyed in many places during the Japanese occupation of Korea from 1910 - 1945, restoration began in 1974. Today, the 2.5 miles that remains of the original fortress makes for a great half-day of hiking. Up high on the mountain, look out over South Korea’s second-biggest city as you step past little streams and ponds, rock caves and granite peaks. 
A perfect escape from the city bustle, with lots of trails and routes to explore, one of the most popular ways to see Mt Geumjeong Fortress and its ornate gates is to begin at Beomeosa Temple. From there, hike up to the South Gate of the fortress, then along the walls and watchtowers to the South Gate, before taking the cable car back down to street level in Geumgang Park, which has its own botanic garden. 

Practical Info

To get to Beomeosa Temple, walk five minutes to Samsin bus stop from Beomeosa subway station (line 1, exit 5 or 7). From there, bus 90 will take you to the temple, from where you can hike up the mountain to Mt Geumjeong fortress. The cable car to Geumgang Park, twenty minutes’ hike from the South Gate, costs 4,000 W one-way or 7,000 W return. Trail signs are in Korean only.