The horizons can be seen by digging a hole or a pit.
This will show the depths of each zone in your soil.
This will also show the natural level of water in the soil for the time of year you are in (water table) and the presence of any pans (hard layers stopping the downward movement of water) (chemical (iron) or cultivation plough pans).

There are many illustrations of simple soil horizons, which can become confusing especially when they start to sub-divide each layer.

see also: soil-profile

The graduation between horizons may be very distinct (old soils) or they may merge gradually with little or no line of demarcation (young soils); The depth and components of the profile are used in classifying soils into types and thereby assessing their potential: Organic soil; Calcareous soil; Grey soil; Grey ash soil; Brown earth; Rendzina; Podzol.