Nearby Nowon is a long freeway that connects the rest of Seoul to this Northeastern portion. It is called the Dongbu Expressway, and is notorious for being slow. It runs parallel next to a river, and I recall the times when I would ride with my ex, how the scenery was pleasant to watch.
Since I live nearby such a feature I figured it would be wise to get out and see it, considering I didn't go at all last year.
I found a smaller stream that connects to the river and so walked down it till it merged with the big path next to the river.