thumb|[[Livanjsko Polje in Bosnia is the largest polje in the world (Mount Dinara visible in the background).]]
A polje, also called karst polje or karst field, is a large flat plain found in karstic geological regions of the world, with areas usually in the range of <!-- -->5–400 km<sup>2</sup> (2–154 sq mi). The name derives from the Slavic languages, where polje literally means 'field', whereas in English polje specifically refers to a karst plain or karst field.
Geology
A polje, in geological terminology,
In Portugal, the town of Minde is located in a landscape of intensive karst. In the summer the polje is fertile fields, in winter, in case of heavy rain, a temporary lake.
The former Lake Copais in Boeotia, Greece, fed subterranean channels (some artificial) until a 1957 land reclamation project drained it completely.
Etymology
In its original languages, the word is synonymous with interior valley. The word polje () itself is of Slavic origin (best known as the root for the country Poland, Polska, from the Polish word pole 'field'). English borrowed polje from Slovene or Serbo-Croatian (, ).