Between the office towers in front of City Hall, step past the lit-up Daehanmun Gate and you'll feel the air change. Deoksugung Palace (덕수궁) stays open until 9 p.m., so office workers on their way home and travelers alike wander in for an evening stroll. Walk past Seogeodang and Jeukjodang, where layer upon layer of eaves overlap, and Seokjojeon Hall appears, a Western-style stone building lined with white columns. Traditional wooden halls and a modern stone building standing side by side within one palace: it's a scene you'll only find at Deoksugung. After you leave the palace, take a walk along Deoksugung Stone Wall Road (덕수궁 돌담길), named one of the Korea Tourism Organization's 100 best night tourism spots. As autumn deepens, the trees along the wall take on richer autumn colors. If you happen to visit on a Wednesday night, admission is free, so it's worth planning around.

Walk just a few blocks from the end of the stone wall road, and the sound of running water begins to drift between the buildings. Take a few steps down and the city's noise falls away by a layer. Once covered by a road, the stream reopened as a public walkway on October 1, 2005. At Cheonggye Plaza (청계광장), the starting point of Cheonggyecheon (청계천), a candle fountain glowing in three colors and a two-tier waterfall dropping 4m are the first to greet you. Twenty-two bridges follow the waterway, their lights stretching long across the water's surface. Couples crossing the stepping stones or resting on benches, and solo travelers strolling along. Open 24 hours with no admission fee, it's the first place we'd recommend if you're after free night view spots in Seoul. Entry is restricted on rainy days, so be sure to check the weather.

Turn your back on the sound of the water and head east, and a silver building made only of curves awaits. Step out of Dongdaemun History & Culture Park Station, and a building that looks like a giant spaceship that has just landed comes into view. Designed by world-renowned architect Zaha Hadid, Dongdaemun Design Plaza (동대문디자인플라자, DDP) has almost no straight lines, its curved surface formed by 45,133 exterior panels, each a different shape. Opened in 2014, it shows a glimpse of Seoul's future amid the Dongdaemun fashion malls that stay lit all night. The indoor facilities close at 8 p.m., but you can keep walking along the illuminated exterior well after that. Be sure to capture the city lights gliding across its silver curves. If your visit lines up with the season, you may also catch "Seoul Light DDP (서울라이트 DDP)," when the entire facade becomes a media-art canvas.

Leaving DDP's lights behind, ride the subway two stops: now it's time to climb the hill along the fortress wall. After dinner in Daehangno, walk uphill through the alleys for about 10 minutes, and the Joseon-era fortress wall will guide your way. Naksan Park (낙산공원) is a hilltop park on the route of Hanyangdoseong, the Seoul City Wall, where a 2.1km fortress trail runs from Hyehwamun Gate past Naksan to Heunginjimun Gate. Lights come on along the stone wall built in the Joseon Dynasty, and beyond it the lights of modern Seoul spread out endlessly. Old fortress and new city, captured in a single frame. The houses clustered along the hillside and the alleys of the Ihwa-dong Mural Village add to the trail's homey charm. Walking the entire fortress trail takes about an hour, so why not take your time on a cool autumn night?

If looking down on Seoul from the fortress wall left you wanting more, head next to the summit of a mountain in the middle of the city. Since 2005, regular passenger cars haven't been allowed up Namsan Mountain. That means the only ways to reach N Seoul Tower (N서울타워) are the cable car, the circular bus, or your own two feet. Walk about 10 minutes from Myeongdong Station and board the cable car, and the lit-up tower draws closer outside the window. From the observatory, downtown Seoul unfolds 360 degrees around you, and the charm of the N Seoul Tower night view is seeing the mountains and the city together. We recommend heading up around sunset to watch the sky shift from orange to navy as the city's lights flicker on one by one. It stays open until 10:30 p.m. on weekdays and 11 p.m. on weekends, leaving plenty of time even for late plans.

Now that you've felt the mountain breeze, how about heading down to the Han River for the river breeze? Find a spot on the riverside lawn, and Banpo Bridge, ordinary by day, shows a completely different face at night. The Banpo Bridge Moonlight Rainbow Fountain (반포 달빛무지개분수) sends Han River water shooting from 380 nozzles along both sides of the 1,140m-long bridge, and in 2008 it entered the Guinness World Records as the "world's longest bridge fountain." The streams of water dance to music, and the lights paint every droplet with color. Shows run every 30 minutes from 7:30 to 9 p.m., each lasting 20 minutes, so grab a few snacks from a convenience store and spread out a picnic mat. Note that the fountain only operates from mid-March through October. If you visit from November onward, stroll along the riverbank enjoying the lights of Sebitseom across the water and the Han River night view.

Once you've had your fill of lights on the water, the final stop is the highest point in Seoul. Follow the underground passage from Jamsil Station into Lotte World Mall, and the Sky Shuttle takes you up to the 117th floor in a single ride. SEOUL SKY (서울스카이) is a 500m-high observatory occupying floors 117 to 123 of Lotte World Tower. Unlike Namsan, where you see Seoul from a mountaintop, here you look down on the city from the top of a skyscraper. Stand on the glass floor of the Sky Deck on the 118th floor, and the lights of Seokchon Lake, the Han River, and the Jamsil area spread out right beneath your feet. On the 120th-floor Sky Terrace, you can take in the night view while feeling the open air. The SEOUL SKY observatory stays open until 11 p.m. on Fridays and Saturdays, making it the perfect place to close out a night in Seoul. From the highest point, you look back over the path you walked today and end the day.

Starting from palace walls, past a stream and a fortress, over a mountain and a river, and finally 500m up in the sky. Seoul's night shows a different face with every step you take. Is there another city where old and new shine together so warmly? This autumn, why not create your own Seoul night view course?