Unification of the ethnic territories took place rather quickly, and already by the 13th century Lithuania had become a political power. A century later, the state took over the huge East Slav territories, extending as far as the shores of the Black Sea. After only a few centuries, however, the state began to disintegrate and finally lost a number of its ethnic lands. Currently, the country covers a smaller area than is inhabited by Lithuanians.

The present territory of the country covers 65,300 km2, with a land boundary of 747 km and a coastline of 99 km. The longest distance from east to west is 373 km, and from north to south 276 km.

Approximately 3/4 of the country's territory consists of lowlands and plains. Most of the landscape is attractive, with undulating terrain in the northeast and west.

From ancient times, Lithuania was alluded to as the land of lakes and forests. Inland water areas cover 4% of the area, forests occupy 27.6%. Most of the lakes, a total of approximately 4000, are found in the north and the south.

The surface of Lithuania is traversed by 722 rivers, the shortest of which is 10 km in length. The largest of them, the Nemunas, rises in Belorus and flours through Lithuania for 475 km.

The climate is a mixture of marine and continental. The average mean temperature in July is +l7.2°C and the average mean January temperature is -4.6°C.

Lithuania's land borders are with Latvia (610 km), Belorus (727 km), Poland (110 km) and the Kaliningrad Region of the Russian Federation, the former Karaliaucius (Königsberg) of East Prussia (303 km). Lithuania has a number of national parks and protected areas. The largest among these is the Aukstaitija National Park, located in the impressive northeastern part. It was established in 1974.