Walk at La Corbière and just opposite on the other side of the trail is La Table des Marthes, a megalith. The table-like stone was used historically as a meeting place for the witnessing of contracts and it is conjectured that the name is a corruption of la table des martyres ("martyr" being intended in its meaning of "witness"). Other theories have been put forward to explain the name and purpose of this stone. Lighthouse The lighthouse is situated on a rock that is a tidal island. A causeway links the lighthouse to shore at low tide. There is an alarm to warn visitors to clear the causeway as the tide rises; still, there have been casualties among the unwary or unlucky. A plaque adjacent to the causeway commemorates Peter Edwin Larbalestier, assistant keeper of the lighthouse, who was drowned on 28 May 1946, while trying to rescue a visitor cut off by the incoming tide. The lighthouse tower is 19 m (62 ft) high and the lamp stands 36 m (119 ft) above high water spring tides. It was lit on 24 April 1874, for the first time, and was the first lighthouse in the British Isles to be built of concrete. The lighthouse was built to designs by Sir John Coode. The beam has a reach of , and was automated in 1976. The lighthouse at La Corbière is one of the most photographed landmarks in Jersey and is a popular tourist site for its panoramic views. In the evenings the surrounding area provides an ideal viewing point for sunsets. Numismatics The lighthouse at La Corbière features on the Jersey 5 pound note (see Jersey pound) and the Jersey 20 pence piece (see coins of the Jersey pound) Culture The prominence of La Corbière, especially for travellers by sea for whom rounding the rocky waters around the headland often means the roughest part of the journey from Guernsey or England but also the consolation that the boat is entering the final straight towards the harbour of St. Helier, has led to several proverbial expressions in Jèrriais: j'avons pâssé La Corbiéthe (we've passed La Corbière, i.e. the worst is over) il a pâssé hardi dg'ieau l'tou d'La Corbiéthe (a lot of water has passed round La Corbière, i.e. that's water under the bridge) MP2 tower At the top of the headland is a range-finding tower that the German occupying