It took us 4 years to find our second 100 benchmarks, but we did it in Tacoma, Washington. I knew part of the old city hall structure was a benchmark (it's the roof of the clock tower). What I did not know was there was a tidal disk on the building. We took some photos of actual building (which is a nice structure) and crossed the street to see if it was on the National Register. While there one of us noticed the disk which became benchmark #200. I know 100 in four years is only 25 a year, but that's almost a benchmark every other week. Hopefully, #300 will be quicker.