With an area of 69,700km2, Georgia is slightly smaller than Austria or the Republic of Ireland, and under half the size of the American state of Georgia. More than half this area lies above 900m and almost 40% (2.69 million hectares) is wooded. The country's dominant feature is, of course, the High Caucasus range which forms its northern border. Although its highest peak, Elbruz (in fact Europe's highest peak at 5,642m), lies wholly within the Russian Federation, Georgia does have three peaks over 5,000m (Shkhara, 5,068m; Janga, 5,059m; and Mkinvartsveri (Kazbek), 5,033m) and ten more over 4,000m. The Caucasus is, like the Himalayas, a very young and dynamic range; it was formed just 25 million years ago, and linked about 15 million years ago to the Iranian Massif. It stretches for roughly 1,200km and contains over 2,000 glaciers, covering an area of 1,780km2.
The High Caucasus falls into three parts. The first of these is the Western Caucasus, stretching 440km from the Black Sea to Elbruz, its highest peak being Dombay (4,046m), on the border with the Russian Federation. It's composed of granite, gneiss and crystalline shales, with limestone and sandstone ridges parallel to the north and west, and is very beautiful with canyons and dense vegetation. The 100km west of Elbruz are higher and more alpine, with glaciers. The Central Caucasus covers the 180km from Elbruz, where the range is at its widest (180km), to Kazbek, where it's at its narrowest (60km), and includes all the peaks over 5,000m. Its western half is granite and shale, and its eastern half andesite and diabase, with a last small spot of granite near Kazbek. Elbruz and Kazbek are very ancient volcanoes, while the peaks between, such as Uzhba, Tetnuldi, Shkhara and Dykhtau, are younger upthrust peaks sculpted by glaciers, with gigantic north faces and lots of scree. Finally, the Eastern Caucasus, from Kazbek to the Apsheron Peninsula, is a confused mass of argillaceous slate, with outcrops of diabase, porphyrite and sandstone; its climate is far drier than to the west, with very little glaciation.
The High Caucasus forms the border with the Russian Federation, but nowhere does Georgia directly adjoin Russia itself; the Muslim peoples of the northern Caucasus, who speak at least 30 different languages, live in half a dozen autonomous republics: from east to west Daghestan, Chechnya, Ingushetia, North Ossetia, Kalbardino-Balkaria and Karachai-Cherkesbaijan (or Circassia).
From almost anywhere in the central valleys you'll be able to see the High Caucasus as a long white wall to the north; in many places you'll also be able to see the Lesser Caucasus, to the southwest along the Turkish border. This is a gentler, more rounded range, rising to 3,301m at Didi-Abuli; the Trialeti Ridge, covered in rich pastures and forests, stretches to the outskirts of the capital, Tbilisi. The two ranges of the Caucasus are linked by the very young Suran (or Likhi) range, which forms the watershed between the Black and Caspian seas and separates eastern and western Georgia, Kartli and Kolkhida.
The country is dominated by one main river, the Mtkvari (Kura in Russian; 1,364km in total), which rises in Turkey, enters Georgia near Vardzia, then flows east through Kartli and Tbilisi and then through Azerbaijan to the Caspian Sea. The main river of western Georgia is the Rioni (327km) which flows from the foothills of Racha through Kutaisi to the Black Sea; others are the Inguri (213km) which flows from Svaneti to the Black Sea, the Iori (320km) and Alazani (351km, the longest within Georgia), which flow through Kakheti and into the Mtkvari, and the headwaters of the Terek (623km in all) which flows north into Russia and eventually into the Caspian Sea.
The main centres of industry and population lie along an east-west axis, from Rustavi through Tbilisi, Gori, Zestaponi, Kutaisi, Samtredia and Senaki to Poti; the only other major cities are two Black Sea ports, Batumi, near the Turkish border, and Sukhumi, in the secessionist republic of Abkhazia.
Georgia has over 2,000 mineral springs producing 130 million litres a day, most of which are wasted. There are over 500 different waters (both hot and cold), of which most contain carbon dioxide, such as those from Borjomi, Sairme and Nabeghlavi; there are also sulphide, nitric and silicon waters (mostly hot), such as those from Tskaltubo, Tbilisi, Nunisi, Tkvartcheli and Makhinjauri, and Gagra, Sukhumi and Aspindza in Abkhazia.
At least 15% of Georgia is limestone, so it's not surprising that there are plenty of fine caves; few of them are set up properly for visitors, but there are great opportunities for exploring. The Gumistavi Cave, near Tskaltubo, is a particularly fine recent discovery, and the Pantiukhin Cave is claimed to be the second deepest in the world at 1,540m. The Tovliana Cave contains snow and ice far underground but has been badly polluted by cavers' rubbish, such as burnt carbide from their lamps. The people of the Tskaltubo area have unwittingly been polluting their own water supply by dumping garbage in caves; some have also been used for agricultural storage and even as hothouses.