Maclear's Beacon is a

triangulation station A triangulation station, also known as a trigonometrical point, and sometimes informally as a trig, is a fixed surveying station, used in geodetic surveying and other surveying projects in its vicinity. The nomenclature varies regionally: they a ...

used in Maclear's arc measurement for Earth's circumference determination. The beacon is on top of

Table Mountain Table Mountain ( naq, Huriǂoaxa, lit= sea-emerging; af, Tafelberg) is a flat-topped mountain forming a prominent landmark overlooking the city of Cape Town in South Africa. It is a significant tourist attraction, with many visitors using the ...

Cape Town Cape Town ( af, Kaapstad; , xh, iKapa) is one of South Africa's three capital cities, serving as the seat of the Parliament of South Africa. It is the legislative capital of the country, the oldest city in the country, and the second largest ...

, South Africa. It is situated on the Eastern end on the plateau of the mountain. MBea

The beacon is above sea level. Table Mountain's higher than the upper cable car station. The structure consists of man made rock packed in a triangle form, being high. It was painted in lamp black colour to make it visible, when light shown on it. In December 1844, the

Astronomer Royal Astronomer Royal is a senior post in the Royal Households of the United Kingdom. There are two officers, the senior being the Astronomer Royal dating from 22 June 1675; the junior is the Astronomer Royal for Scotland dating from 1834. The post ...

at the

Cape A cape is a clothing accessory or a sleeveless outer garment which drapes the wearer's back, arms, and chest, and connects at the neck. History Capes were common in medieval Europe, especially when combined with a hood in the chaperon. Th ...

Thomas Maclear Sir Thomas Maclear (17 March 1794 – 14 July 1879) was an Irish-born South African astronomer who became Her Majesty's astronomer at the Cape of Good Hope. Life He was born in Newtownstewart, County Tyrone, Ireland, the eldest son of Rev Jam ...

, instructed his assistant William Mann to build a beacon in the form of a pile of rocks which would be used to confirm and possibly expand on the existing curvature of the earth data of

Nicolas-Louis de Lacaille Abbé Nicolas-Louis de Lacaille (; 15 March 171321 March 1762), formerly sometimes spelled de la Caille, was a kingdom of France, French astronomer and geodesist who named 14 out of the IAU designated constellations, 88 constellations. From 1750 ...

. This data was in connection with the Cape

arc of the meridian In geodesy and navigation, a meridian arc is the curve between two points on the Earth's surface having the same longitude. The term may refer either to a segment of the meridian, or to its length. The purpose of measuring meridian arcs is to ...

. Initially the beacon had no name but in later years it was named after Maclear. In 1929, the pile of stones collapsed and it was restored in 1979 to commemorate the centenary of Maclear's death. The beacon is still used by cartographers today. It has become a tourist attraction and hiking trails over the mountain pass next to the beacon. It is also a National Monument.

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* 1844 in South Africa Buildings and structures completed in 1844 Buildings and structures in Cape Town Geodesy Geomatics {{geodesy-stub