I thought I'd heard the reason for the name for Falkirk, but after googling it - I clearly hadnt; "The Scottish Gaelic name was calqued into Scots as Fawkirk (literally "variegated church"), then later amended to the modern English name of Falkirk. The Latin name Varia Capella also has the same meaning." - comes from wikipedia.
Interestingly I did hear about a potential meaning for Stenhousemuir recently, which is another town very close to Falkirk. They reckon it comes from Stenhouse, or Stone House, referring to a Roman Temple that stood there from the time of the Roman invasion of Scotland (then Caledonia) - dating back to something like 100-200 AD. The temple called Arthurs O'on, was actually intact until the 1700s when a total twat pulled it down to use the stonework to make a weir in the river, which then got washed away in a storm. I'm still raging about it !