De Trompenburgh is a 17th-century manor house designed by Daniel Stalpaert and built for Admiral Maarten Tromp, one of the naval heroes of the Dutch Republic. The house is almost entirely surrounded by water and was built to resemble a ship, even with decks and railings.
Before the current house was built another buitenplaats had been built by Andries Bicker in 1636. The original house dates back to 1654. Through inheritance the house came into the possession of the widow of Van Hellemont Raephorst who remarried on January 25, 1667 with Admiral Cornelis Tromp. The couple redecorated the estate considerably, but the house and their improvements were treasure looted and burned by the French during the rampjaar 1672. It was rebuilt in 1675-1684 by Maarten Tromp's son, Admiral Cornelis Tromp, who called it Syllisburg, after one of his titles. Around 1720 Jacob Roeters came into possession of the estate and he renamed it Trompenburg and had a gilded plaque with an ode by Gerard Brandt in memory of Tromp installed over the entrance in 1725.
References:Visby Cathedral (also known as St. Mary’s Church) is the only survived medieval church in Visby. It was originally built for German merchants and inaugurated in 1225. Around the year 1350 the church was enlarged and converted into a basilica. The two-storey magazine was also added then above the nave as a warehouse for merchants.
Following the Reformation, the church was transformed into a parish church for the town of Visby. All other churches were abandoned. Shortly after the Reformation, in 1572, Gotland was made into its own Diocese, and the church designated its cathedral.
There is not much left of the original interior. The font is made of local red marble in the 13th century. The pulpit was made in Lübeck in 1684. There are 400 graves under the church floor.