Lake Ohrid (Macedonian: Охридско Езеро, Ohridsko Ezero; Albanian: Liqeni i Ohrit) straddles the mountainous border between the southwestern Macedonia and eastern Albania. It is one of Europe's deepest and oldest lakes, preserving a unique aquatic ecosystem with more than 200 endemic species that is of worldwide importance. The importance of the lake was further emphasized when it was declared a World Heritage site by UNESCO in 1979 and when, in 2010, NASA decided to name one of Titan's lakes after Lake Ohrid.

Lake Ohrid is the deepest lake of the Balkans, with a maximum depth of 288 m (940 ft) and a mean depth of 155 m (508 ft). It covers an area of 358 km² (138 sq mi), containing an estimated 55.4 km³ of water. It is 30.4 km long by 14.8 km wide at its maximum extent with a shoreline length of 87.53 km, shared between Macedonia (56.02 km) and Albania (31.51 km).

The Ohrid and Prespa Lakes belong to a group of Dessaret basins that originated from a geotectonic depression during the Pliocene epoch up to five million years ago on the western side of the Dinaric Alps. Worldwide, there are only a few lakes with similarly remote origins with Lake Baikal and Lake Tanganyika being the most famous. Most other, short-lived lakes have a life span of less than 100,000 years before they are eventually filled up with sediments. It is believed that in the case of Lake Ohrid this process was delayed by its great depth and small sediment input from its filtered spring inflows. Moreover the Ohrid-Korca graben to the south of the lake is still tectonically active and might compensate sedimentation by subduction. In contrast to Lake Ohrid, Lake Prespa is likely to have turned dry several times in its history, as a result of its karstic underground. In 2008, Macedonian media reported that international experts will be researching the lake in order to determine its age.

Coordinates: 41°07′01″N 20°48′06″E / 41.11694°N 20.80167°E / 41.11694; 20.80167

Ohrid (Macedonian: Охрид [ˈɔxrit] ( listen)) is a city on the eastern shore of Lake Ohrid in the Republic of Macedonia. It has about 42,000 inhabitants, making it the seventh largest city in the country. The city is the seat of Ohrid Municipality. Ohrid is notable for having once had 365 churches, one for each day of the year and has been referred to as a "Jerusalem". The city is rich in picturesque houses and monuments, and tourism is predominant. It is located southwest of Skopje, west of Resen and Bitola, close to the border with Albania. In 1979 and in 1980, Ohrid and Lake Ohrid were accepted as a Cultural and Natural World Heritage Sites by UNESCO. In fact, Ohrid is one of only 28 sites that are part of UNESCO's World Heritage that are both Cultural and Natural sites.

In Macedonian and the other South Slavic languages, the name of the city is Ohrid (Охрид). In Albanian, the city is known as Ohër or Ohri. These names come from Latin Lychnidus and ancient Greek Lychnidos (Λύχνιδος); modern Greek Ochrida (Οχρίδα, Ωχρίδα) and Achrida (Αχρίδα) are borrowed from Slavic.