The western part is the Hortobágy National Park ("Puszta"), a large flat area of the country.

It seems that the county slopes to the south because the lowest point is situated in this part of Hajdú-Bihar and hits the 85 metres height.

[citation needed] The wind and rivers formed and shaped the land for thousands of years.

The wild and rapid rivers of the mountains slowly made that inland sea disappear.

The roads cross the national borders to Romania at the cities of Ártánd and Nyírábrány.

The four largest cities – both by area and by population – are Debrecen, Hajdúböszörmény, Hajdúnánás and Hajdúszoboszló.