Langjökull is the second largest ice cap in Iceland (953 km2), after Vatnajökull. It is situated in the west of the Icelandic interior or Highlands of Iceland and can be seen clearly from Haukadalur.

The glacier is located at 64°45′N 19°59′W.

Its volume is 195 km³ and the ice is up to 580 m (1,900 ft) thick. The highest point of the ice cap (at Baldjökull at the northern end of Langjökull) is about 1,450 m (4,760 ft) above sea level.

In the past, the largest recorded surface area was in 1840.

The glacier is roughly parallel to the direction of the country's active volcanic zone: north-east to south-west. It is about 50 km (31 mi) long and 15 to 20 km (9.3 to 12.4 mi) wide, and has a slightly narrower point roughly between the lake Hvítárvatn on the Kjölur mountain road to the east and the Þrístapajökull glacier to the west, near another smaller glacier, Eiríksjökull, which is not quite connected to Langjökull. It is the nearest large glacier to Reykjavík.

The area of the glacier includes some mountains, e.g. Jarlhettur ("The earl's hat") on the east side of Langjökull, a palagonitic mountain range, which originated in a fissure vent under a glacier during Ice Age.

The mountain Skríðufell (1,235 m (4,052 ft)) is situated on the east, above lake Hvítárvatn. Other mountains on the eastern side of Langjökull are Fjallkirkja (1,177 m (3,862 ft)), Þursaborg (1,290 m (4,230 ft)) and Péturshorn (1,370 m (4,490 ft)).

A little to the east of Fjallkirkja is the hut of the Icelandic Glacier Research Society (Jöklarannsóknarfélag), which includes scientists as well as interested amateurs.

Source: https://en.wikipedia.org/wiki/Langj%C3%B6kull