
The Thriasio Plain ( el, Θριάσιο Πεδίο, translit=Thriasio Pedio) is a plain in western
Attica
Attica ( el, Αττική, Ancient Greek ''Attikḗ'' or , or ), or the Attic Peninsula, is a historical region that encompasses the city of Athens, the capital of Greece and its countryside. It is a peninsula projecting into the Aegean Se ...
, immediately to the west of
Athens
Athens ( ; el, Αθήνα, Athína ; grc, Ἀθῆναι, Athênai (pl.) ) is both the capital and largest city of Greece. With a population close to four million, it is also the seventh largest city in the European Union. Athens dominates ...
, in
Greece
Greece,, or , romanized: ', officially the Hellenic Republic, is a country in Southeast Europe. It is situated on the southern tip of the Balkans, and is located at the crossroads of Europe, Asia, and Africa. Greece shares land borders with ...
. It is bounded by
Mount Egaleo to the east, Mount
Parnitha
Mount Parnitha ( ell, Πάρνηθα, , Katharevousa and grc, Πάρνης ''Parnis''/''Parnes''; sometimes Parnetha) is a densely forested mountain range north of Athens, the highest on the peninsula of Attica, with an elevation of 1,413 m, and ...
to the north, Mount