Its seat was in Vainikkala near the border with Russia, however the largest settlements were Laihia and Lavola near Lappeenranta and Lauritsala.

Lappee bordered Lappeenranta, Lauritsala, Joutseno, Nuijamaa, Ylämaa, Luumäki, Lemi and Taipalsaari.

The lap- element is generally thought to be etymologically connected with the name of Lapland, which may suggest that Sámi people have lived in the area.

The village of Kauskila was among the most significant Karelian population centers in South Karelia during the Middle Ages.

The first parish to be separated from Lappee was Taipalsaari in 1571, which also included Lemi, Savitaipale, Suomenniemi and a part of Mäntyharju.