Towards the east end (#1) of this walk along Kaigan-dori, if you're up early enough, you can see the fisherfolk hauling in their catch. Styrofoam containers and weathered ropes litter this part of the port. There are also old, probably abandoned buildings along the port.
Towards the west end (#2) is where all the metal scrapping happens. You can peek into factories (don't get in the way!), check out the compacted cubes of aluminium cans or admire the enormous mountains of metal if they haven't already cleared them. There are two small playgrounds on the walk.
Around the middle of October every year is Niihama's (in)famous Taiko Festival. Grown men fuelled on too much beer and not enough sleep carry enormous, heavy taiko housings on their shoulders and parade them around. The bad boys of the festival will ram the housings into each other, which results in their teams being banned the following year. Kaigan-dori is a popular place to watch this happen -- just follow the crowds. And be careful where you stand!