Changdeokgung was built in 1405 as a secondary palace for the Joseon kings, and it ended up being the one they actually liked living in. Where the main palace, Gyeongbokgung, was laid out on a strict axis, Changdeokgung was fitted into the foot of the hills, following the folds of the ground, and its halls, gates and courtyards feel more relaxed and more human as a result. After the Japanese invasions of the 1590s burned all of Seoul's palaces, this was the first to be rebuilt, and it served as the main royal residence for some two and a half centuries.
The highlight is the garden behind the palace, known as Huwon or the Secret Garden. It covers a wooded valley with ponds, pavilions, a library where young scholars studied, and paths that wind under old trees. The most famous view is the square pond of Buyongji with a pavilion standing with its feet in the water, an image of the old Korean idea of a square earth and a round heaven. Access to the garden is by timed guided tour, with limited numbers, so book ahead or arrive early, especially in autumn when the maples blaze and every Seoul resident with a camera wants a ticket.
The palace sits right in the old heart of Seoul. Next door is Changgyeonggung, another palace linked by gates and paths, and just to the west lies Bukchon, a hillside district of traditional hanok houses with tiled roofs and narrow lanes. Ikseon-dong, a little to the south, has turned its old alleys into cafés and small restaurants. On a weekday morning you can walk through four or five centuries of the city in a couple of hours.
For a rider, Seoul is an exercise in patience and alertness. Traffic is dense, delivery scooters dart everywhere, and motorcycles are banned from the national expressways and the city's urban expressways, so you will be on surface roads with plenty of traffic lights. Park outside the palace and walk; the old quarter is a place for feet, not wheels. The best riding out of the city starts once you cross the northern ridges toward the hills.
Fuel, food and coffee are everywhere. The markets of nearby Jongno serve everything from mung-bean pancakes to bowls of rice with raw beef, and Gwangjang Market in particular is a lively, steamy place to eat standing at a counter among the locals before heading back to the bike.