Fort Grey is a Martello tower located on a rock in Rocquaine Bay. It was previously the site of local witches' Sabbaths. The existing fort, with its white tower was originally built as a defence by the British in 1804 during the Napoleonic Wars, it was named after Charles Grey, 1st Earl Grey, who was Governor of Guernsey from 1797 to 1807.
The Fort Grey tower, like the other two Guernsey Martello towers, Fort Saumarez and Fort Hommet, was intended as a keep for the battery in which it was placed. The Guernsey Martellos are smaller than the British towers, with the Fort Saumarez and Fort Hommet towers being smaller than the Fort Grey tower. Each mounted a 24-pounder carronade on the roof to protect the battery. Fort Saumarez and Fort Hommet also have exterior staircases up to the second floor. The War Office in London sold Fort Grey to the States of Guernsey in 1891 for £185.
During the Occupation of the Channel Islands in World War II, the Germans occupied the fort, as they did most of the other fortifications in Guernsey. More recently Fort Grey has been adapted for other more peaceful uses and now operates as a local shipwreck museum, housing a number of items of marine salvage from famous wrecks, including the MV Prosperity and Elwood Mead. The items also include a cannon from HMS Boreas that points towards the nearby Hanois rocks where Boreas sank in 1807 with the loss of her captain, at least half her crew, and possibly the captain's wife.
References:Rosenborg Palace was built in the period 1606-34 as Christian IV’s summerhouse just outside the ramparts of Copenhagen. Christian IV was very fond of the palace and often stayed at the castle when he resided in Copenhagen, and it was here that he died in 1648. After his death, the palace passed to his son King Frederik III, who together with his queen, Sophie Amalie, carried out several types of modernisation.
The last king who used the place as a residence was Frederik IV, and around 1720, Rosenborg was abandoned in favor of Frederiksborg Palace.Through the 1700s, considerable art treasures were collected at Rosenborg Castle, among other things items from the estates of deceased royalty and from Christiansborg after the fire there in 1794.
Soon the idea of a museum arose, and that was realised in 1833, which is The Royal Danish Collection’s official year of establishment.