Bailou Road is located in New York. It is 256.6 meters long with an average gradient of 11.7% and a maximum gradient of 22.8%. Find similar hills.
Realizing I had missed my turn (on what turned out to be an abandoned dirt road) I turned around. A woman outside her house yelled "what, turning around before the hill?!?" I stopped and talked to her, and she informed me that there was a "nasty" hill just up the road. And she wasn't kidding. The section of <20% is long enough and steep enough to qualify as a wall, though not so long as to present any serious problems.