A friend of mine got a temporary job updating the cadastral maps in his state. He took the job because it paid very well, and I don't think he knew what all he would be getting into at first.
He had to compare current data with old records, and he had to do a lot of research. He worked long hours doing tedious work, though the product of his labor was valuable to many people.
Before he took that job, I never even knew that cadastral maps existed. Now, I'm intrigued by them, because I know the vast amount of details that they contain.