Slope of the ground unknown [HD99]

The slope of the ground is unknown. It is impossible to determine the slope, as information is unavailable, or the building has not been inspected sufficiently to determine the slope of the ground.

This building in Vancouver, Canada was built on a sloped ground, however the slope (in terms of number of degrees) is unknown (S. Brzev)

Buildings in this street in Lisbon, Portugal were built on a sloped ground, however the slope information is not available (S. Brzev)