There is a great example doing the rounds on social media at present of the power of satellite imagery for mapping changes in the landscape. Google Earth Timelapse combines all of the available archive Landsat digital imagery (from approximately 1980 on so I'm guessing L4 is the earliest) to present almost 40 years of continuous imagery for looking at changes in the landscape. The really powerful thing is that this is available in a web broswer for anywhere in the world. Just zoom, pan and move the slider. No processing or RS knowledge needed to use it.
See the excellent example below - changes in the course of the river in Tibet over the period.
|40 years of Landsat data for river monitoring|
I looked for Irish examples but even changes in Dublin through the Celtic tiger era are a bit hard to make out, partly because we get so many cloudy days and there is therefore less data for a smooth animation. Line banding on the Landsat 5 sensors in Dublin bay also makes it look a bit messy. The construction of the islands in Dubai is well worth a look to get you started.