For me and many other travellers, Miri is the perfect stop-over city. Most people stay a night in Miri in order to get to Mulu National Park. I, however, stayed there before I visited Brunei. I even had a bit of time to explore Miri.
Miri’s old city centre looks like any old city centre. It is nice to see but nothing special. There are two major sites that I would recommend. The first one is The Grand Old Lady or also known as Miri Well. The Grand Old Lady was the first oil well of the country and you can still see the well. There is also a museum there, although it was closed when I was in Miri. I could not find anything online about the closure, so I have no idea if the museum is opening again. Since the well is on a hill, the view from up there is rather beautiful so I would recommend going regardless of the museum. There is no bus going to Miri Well, so you have to either take a Grab or a taxi.
The other place in Miri you should definitively visit is Tanjung Lobang or also known as Brighton Beach. This beach is actually famous for its beautiful sunsets, unfortunately, I did not catch it as I was there around midday. It is still a nice beach, albeit full of rubbish. I also took a Grab there, so I have no idea if there is bus going there. However, a Grab from The Grand Old Lady to Brighton Beach was only about RM9 (~€1,80 or ~$2,10)
Have you ever been to Miri? Have I missed something? Let me know in the comments.