an abnormally weak magnetic field. On 14 November 2008 a geomagnetic observatory was inaugurated on the island as part of a joint venture between the Danish Meteorological Institute and DTU Space. Transport The remote location of the islands makes transport to the outside world difficult. Tristan da Cunha has no airstrip and is not generally accessible to air travel, though the wider territory is served by Saint Helena Airport and RAF Ascension Island. Fishing boats from South Africa service the islands eight or nine times per year. The RMS Saint Helena used to connect the main island to St Helena and South Africa once each year during its January voyage, but has done so only a few times in the last years, in 2006, in 2011, and most recently in 2018. In the same year the RMS St. Helena was withdrawn from service. Three ships regularly service Tristan da Cunha, with typically fewer than a dozen visits a year. Other vessels may occasionally visit the island. The harbour at Edinburgh of the Seven Seas is called Calshot Harbour, named after the place in Hampshire, England where the islanders temporarily stayed during the volcanic eruption. Tourism Unlike Saint Helena with its airport, hotels and restaurants, due to its remoteness Tristan da Cunha has a very small tourism industry. Tourists are welcome and the hospitality of the population is famous, but as it can only be reached by South African fishing trips in rough seas with limited vacancies, a trip must be planned months in advance, and only after a mandatory visit request is approved by the Island Council. Occasional boats or cruises may include a short visit to the island in their itinerary; but as there is no deep harbour, setting ashore is highly dependent on the maritime conditions. With all these limitations and in spite of the spectacular natural landscapes, visiting the territory is an attractive challenge for more adventurous travellers who can afford the time and money to get there. All visitors staying on Tristan must have a confirmed and fully paid return ticket, health insurance to include cover in case of medical evacuation to Cape Town, and sufficient funds to cover their entire stay. There are no hotels on the island. A visitor can rent a guest house (catered or self-catering) or stay in a private home on a full-board basis. There is a Tourism Post Office that