Recommended time to visit: spring, summer, fall
Recommended for solo travelers and an inexpensive date-day for couples
One cheap thing that I love to do is go to 한강/Han River. All you really need is a way to get there and maybe a few bucks to make some ramyun (Korean ramen).
In general, you can enter the Han River from anywhere, really. Many main entrances will have the same things: food, bike rentals, spots to have a picnic, etc.
If you want to have some ramyun made in a special little machine, however, may I recommend searching for 반포 한강공원/Banpo Hangang Park. There's a GS25, a convenience store, that has ramyun making machines!
Making ramyun is surprisingly easy. Go into the store, pick out a flavor, buy it, and then come out and go to the machine.
The How To
Put your noodles, seasoning, and veggies packet into the bowl
Find the bar code on the bowl
Scan it in the area on the bottom right. **It can be tricky!
The timer will appear
Press the read button that looks like a stop button (this was the most confusing part for me lol)
Water will come out of the spout at the bottom
Enjoy it bubbling and boiling
Once the timer goes off, find a seat and enjoy!
Once you're finished, you'll find the garbage and recycling close to the doors.
There's a place to put your bowl, empty out any remaining juice or noodles, a place to put chopsticks, and your usual bottles and cans section. I really wish more places in the U.S. implemented this type of disposal system!
There you have it! After eating you can keep walking the trails or head on over to Seoul Forest and see the few sights around there! Han River is a popular place, I hope you try it out!