Two way trip. The height differences on speedway ramp are propably correctly recorded, but the differences in the upper part of the trace are due to pausing geolocation for a while, and restariting between fairly high buildings. Vertical accuracy is inferior to horizontal and speed accuracies.

In reality the highest point was below 20m, and I certainly stayed above sea level. Ascent and descent values accumulate the errors: especially when walking beteween buildings on rocks, don’t expect these to be accurate.

As it should, lowest (black) altitude is found when walking at the sea shore.