The 15th- or early 16th-century tower house was built by the Dalzell family, who acquired these lands in the 13th century. Thomas de Dalzell fought at the Battle of Bannockburn in 1314. Sir Robert Dalzell forfeited the lands in around 1342, for residing in England without the King's consent, but they were restored through marriage in the 15th century. Another Sir Robert Dalzell was created Lord Dalzell in 1628, and his son was further elevated as Earl of Carnwath in 1639.
In 1645 the Earl of Carnwath granted the Dalzell estate to his nephew James Hamilton of Boggs, who built the first major extensions to the tower house, adding the south wing around 1649. By 1750, avenues of trees had been laid out in the grounds, probably the work of Archibald Hamilton, 4th of Dalzell. The 7th Hamilton laird, another Archibald Hamilton, entered into a venture with the reformer Robert Owen. An attempt was made to build a model settlement at the Hamiltons' nearby property of Orbiston, but this proved an expensive failure.
In the 19th century the family's fortunes were enhanced by the Lanarkshire coal mining boom, and in the 1850s John Hamilton (1829–1900), a Liberal politician later ennobled as Baron Hamilton of Dalzell, commissioned a major remodelling of the house. Architect Robert William Billings carried out extensive restorations to the earlier buildings, and added a new north wing. The south wing was also restored in 1869, following a fire. Lord Hamilton served in the government of William Gladstone, who visited Dalzell on several occasions, and the Prince and Princess of Wales visited in 1888.
On the death of the 2nd Baron in 1952, the property was sold out of the Hamilton family. Part of it was used as Gresham House Boys' Boarding school from 1954 until 1967, when it was purchased by Motherwell and Wishaw Town Council. The house then stood empty until the 1980s when developer Classical House renovated the property as a series of 18 private apartments. The interiors retain Billings' Jacobean detailing.References:
The Petersberg Citadel is one of the largest extant early-modern citadels in Europe and covers the whole north-western part of the Erfurt city centre. It was built after 1665 on Petersberg hill and was in military use until 1963. It dates from a time when Erfurt was ruled by the Electors of Mainz and is a unique example of the European style of fortress construction. Beneath the citadel is an underground maze of passageways that can be visited on guided tours organised by Erfurt Tourist Office.
The citadel was originally built on the site of a medieval Benedictine Monastery and the earliest parts of the complex date from the 12th century. Erfurt has also been ruled by Sweden, Prussia, Napoleon, the German Empire, the Nazis, and post-World War II Soviet occupying forces, and it was part of the German Democratic Republic (East Germany). All of these regimes used Petersberg Citadel and had an influence on its development. The baroque fortress was in military use until 1963. Since German reunification in 1990, the citadel has undergone significant restoration and it is now open to the public as a historic site.