Seoul or Busan?

Busan has real beaches inside the city. Haeundae is a wide arc of sand, Gwangalli looks across at the lit-up bridge and Songjeong suits beginner surfers, and all of them can be reached by metro. The swimming season is short, though, running from July to early September, and Haeundae is packed during the peak weeks.

Seoul's nearest beaches are on the Yellow Sea beyond Incheon, an hour or more away. There the tide pulls far back over mudflats and the water is rarely clear. In summer people in Seoul swim in the outdoor pools of the Han River parks instead, and anyone who wants the sea is better off in Busan.

Busan's cooking has a narrower range but is very much its own. You choose live seafood at Jagalchi and eat it upstairs, and the city adds milky dwaeji gukbap served all night, icy milmyeon noodles and fishcake skewers, with grilled clams and soju in the tent bars by the shore.

Seoul goes further. Table barbecue, stone-pot stews and the mung bean pancakes of Gwangjang Market are the everyday food. Above them are modern Korean fine dining, temple cuisine and the design-led cafés of Seongsu and Yeonnam-dong. Neither city is strong on international cooking.

Seoul has much more heritage to see. It has five Joseon palaces, including Changdeokgung with its secret garden, as well as the Jongmyo shrine, the hanok lanes of Bukchon and the National Museum of Korea, one of Asia's great collections. Several days are easily filled.

Busan grew quickly around its port during and after the war and has little old townscape. Its best sights are temples, Beomeosa in the mountains and Haedong Yonggungsa on the rocks above the sea. Add the painted hillside of Gamcheon and the UN Memorial Cemetery, and you have enough for two or three days.

Both cities go out the Korean way, with rounds of soju and beer and then karaoke, running late. Seoul does it on a far larger scale. Hongdae keeps its clubs and street buskers going until the first trains, Itaewon has the most international crowd and Gangnam has the big, dressed-up clubs.

Busan is better for moving between bars than for clubbing. Seomyeon is the busiest area, the bars at Gwangalli look across at the bridge, and evenings are at their best in summer by the shore.

In both cities you can start a hike from a metro station, and spring and autumn are the best seasons in each. What differs is the setting. Busan's walking is along the coast: the Igidae cliff path, the lighthouse on the Taejongdae headland and the long Galmaetgil trail, with surfing and sailing in summer.

Seoul's outdoors are granite mountains and the river. Bukhansan National Park lies inside the city limits, Inwangsan gives a short climb with views over the palaces, and cycle paths run for many kilometres along the Han.

The two are evenly matched for day trips, but each opens up a different part of Korea. From Busan, the royal tombs, Bulguksa and Seokguram of Gyeongju are half an hour away by fast train. The harbour at Tongyeong, the spring cherry blossom of Jinhae and a ferry to Japan's Tsushima are also within reach.

From Seoul, Gyeongju is too far for a comfortable day. Instead you get Suwon's walled Hwaseong Fortress, the hanok quarter of Jeonju and organised tours to the Demilitarized Zone, a trip only the capital can offer.

Seoul is the easier city with children. Lotte World is in town, Everland and its safari are about an hour south, and the zoo, aquariums and science centres are well run. Subway stations have lifts and clean toilets.

Busan works well for a summer trip built around the beach. It has the seafront aquarium at Haeundae, the theme park and luge in Gijang, and the slow sky-capsule rail along the coast. Its hills, temple steps and long distances make the days harder going with small children.

Busan's metro is clean, cheap and signed in English, and one tap card covers it and the buses. The difficulty is the city's shape. Busan is squeezed into a long, narrow strip between the hills and the sea, so journeys add up: getting from the old port at Nampo-dong to the beaches at Haeundae means changing at Seomyeon and takes the best part of an hour. Gamcheon, the coastal temples and the Taejongdae headland are off the network, so reaching them usually means a bus and then a steep climb on foot.

In Seoul the subway reaches more of what a visitor wants to see, from the palaces to Gangnam, Hongdae and the trailheads for Bukhansan, and most stations have lifts and platform doors. The city is far larger, and crossing from the old centre to south of the river can take 40 minutes with changes, so it pays to stay near the area you will use most. Neither city calls for a car.

Seoul is one of Asia's great shopping cities. Myeongdong is lined with skincare shops, Cheongdam has the luxury flagships and Garosu-gil and Hannam-dong have Korean designers. Dongdaemun's fashion malls trade through the night, and Insadong sells celadon and hanji paper.

Busan's shopping is about size rather than style. The huge department stores of Centum City and the underground arcades of Seomyeon cover the practical side, and dried seafood from the markets around Nampo-dong is the best thing to take home.

Busan works out a little cheaper. Soup restaurants, market meals and street snacks cost little, and the temples, markets and coastal walks are mostly free. Costs climb with beachfront hotels in July and August and with seafood sold by weight.

In Seoul, casual meals and the subway are just as good value. Hotels in Myeongdong and Gangnam, barbecue dinners and coffee in the smarter cafés push the cost of a trip higher.

Seoul has far more worth booking. The Seoul Philharmonic, opera and ballet play at the Seoul Arts Center and the Sejong Center, and the National Gugak Center stages court music. Daehangno has percussion and martial arts shows that need no Korean, and Hongdae has indie bands.

Busan has a good concert hall in Citizens' Park and touring musicals at Munhyeon, mostly in Korean. What stands out is its film festival, held every autumn at the Busan Cinema Center, and summer brings large outdoor rock and K-pop events.

Both cities are good places to bathe, and a body scrub followed by a long soak is easy to arrange in either. The difference is the water. Busan's baths are fed by natural hot springs, above all at Dongnae, a spa district since the Silla era, and the city's slower pace adds evening walks along the seafront.

Seoul has round-the-clock jjimjilbang bathhouses on almost every block, plus skincare spas and foot massage. The city itself is loud, though, so calm comes in pockets: the palace gardens, the Insadong teahouses and the river at dusk.