A benchmark is a geographic point whose elevation has been measured and recorded to a high level of accuracy. The height of a benchmark is calculated relative to the heights of nearby benchmarks in a network extending from a fundamental benchmark (a point which records a height to extreme accuracy). Benchmarks are […]

Across Great Britain is a network of benchmarks. There used to be about half a million benchmarks, but as they have become obsolete, about half have disappeared. The first primary leveling in the UK was carried out in 1841-60, the second in 1912-21, and the third in 1951-56. The horizontal bar above […]

In one of Lviv’s courtyards I stumbled across a curious sign pointing to a water level. My first thought was that it is a benchmark—a point of known elevation marked for the purpose of surveying. However, unlike the other prewar benchmarks that I have seen in Lviv—small metal plaques with […]

Throughout the centuries many disastrous floods struck Prague. In particular, one such flood struck September 2-5, 1890. I came across a few memorial plaques which mark the level reached by the floodwaters. Výška vody  4. září 1890 Water level  4 September 1890

Berehovo, or “Ukrainian Hungary,” is a town in Zakarpattia, located only 5 km from the Hungarian border. For most of its history it was part of Hungary, and so this heritage is still strongly visible in the cityscape (all street signs, many shop signs, etc., are in both Hungarian and […]

I found an old benchmark in Przemyśl, Poland, located on a little post near the city’s central river, the San. You can read more about benchmarks in this post about Lviv’s benchmarks. The outer ring reads “Znak Wysokosci” (Height Marker), followed by 2 letters and 4 numbers, looks like AA-0001, […]