Pivško podolje (ali Pivka) je pokrajina ob reki Pivki obdana z visokimi kraškimi planotami. Pokrajinske razlike (predvsem kamninske) delijo pokrajino na Zgornjo ali Podsnežniško in Spodnjo ali Podnanoško Pivko. Spodnja Pivka obsega najširši del podolja in ji pravijo tudi Postojnska kotlina ali celo Postojnsko polje.
Zgornja Pivka (kamor seže tudi razgled ) obsega pretežno kraški svet med Prestrankom in Šembijami, Spodnja Pivka pa leži ob stalnem toku Pivke od Prestranka navzdol, predvsem pa v porečju Nanoščice. Je iz flišnih kamnin (laporovcev, peščenjakov in konglomeratov) odloženih v eocenu. Te kamnine so vododržne, zato se je na njih razvit rečno-denudacijski relief z oblimi griči ter vmesnimi plitvimi in ploskimi dolinami. Dna dolin prekrivajo rečni nanosi, predvsem pesek, ilovica in nekaj proda.
Pivško podolje predstavlja nekakšno streho notranjskega krasa, od koder se ob apneniškem obrobju razlivajo vode v različne smeri. Tu poteka razvodnica med Črnim in Jadranskim morjem.
(Vir: http://www.razvojkrasa.si/si/relief/149/article.html)
Pivka basin (or Pivka) is an area of the Pivka river surrounded by high karst plateaus. Areal differences (mostly rock) divifde the landscape in the Upper and Lower or Podsnežniška and Podnanoška Pivka. Lower Pivka comprises the widest part of the valley and also called the Postojna basin or even Postojna field.
Upper Pivka (seen from the cache location) comprises mainly karst terrain between Prestranek and Šembije, Lower Pivka lies on both sides of the constant stream of Pivka down of Prestranek, especially in the basin of river Nanoščica.Bedrock is flysch (marl, sandstone and conglomerates) deposited in eocene. These rocks are impermeable, so here developed the river-denudational relief with round hills and intermediate shallow and flat valleys. At the bottom of the river valley overlap layers, mainly sand, clay and some gravel.
Pivka basin represents a sort of roof of Notranjska karst, from where at the limestone outskirts waters run in different directions. This forms the watershed between the Black and the Adriatic Sea.
(Source: http://www.razvojkrasa.si/si/relief/149/article.html)