I had a lot of trouble throughout my year teaching near Busan that I recieved a lot of unwanted attention from Korean middle-aged men harassing me and asking me if I was Russian. (They are essentially asking if you are a prostitute) I was by the way wearing normal clothing of a jumper and a coat etc, and many times these incidents occured in the middle of the day. Some of the time it was a passing comment, but I had a couple of occasions where men would literally try to drag me into a taxi or push money in my hands. Overall a very negative aspect of my time living there, it was humiliating and traumatic.
Walking the fortress wall was not at all what I thought it would be. I had visions of a real wall with many gates and towers... what I got was a long walk with nothing much to look at. The fortress wall itself is that impressive, and usually about 2 feet high. that is not a typo... 2 feet high only. As well, all the gates look similar.
DO THIS INSTEAD... Start from Beomesa temple and hike up to the fortress gate. The gate there is impressive and the wall is just as good or better than the rest of the places. You can also hike a little more up the wall and see a view point. but then you should just hike back down to the temple.
if you do continue the hike, it will be about 5 hours until the you reach the other end. On a nice day, it might be enjoyable, but on a cold/hot day its just going to suck.
Busan is more prone to typhoons than any other city in Korea. The worst ones seem to strike in September. Typhoon Maemi, in September 2003, had wind speeds of up to 216kph, killed more than 100 people, overturned ships and cars, toppled giant cranes, snapped power lines, derailed trains and destroyed buildings.
If you are planning to visit Busan around that time of year, heed typhoon warnings.
ALWAYS ALWAYS ALWAYS bring some toilet paper with you no matter where you go. You will be glad you did....most bathrooms don't provide toilet paper...and sometimes the toilet paper vending machines located outside the bathrooms don't work.