The Botanic Gardens of Belfast opened in 1828 as the private Royal Belfast Botanical Gardens. It continued as a private park for many years, only opening to members of the public on Sundays prior to 1895. Then it became a public park in 1895 when the Belfast Corporation bought the gardens from the Belfast Botanical and Horticultural Society.
Occupying 28 acres (110,000 m2) of south Belfast, the gardens are popular with office workers, students and tourists. The gardens' most notable feature is the Palm House conservatory. It was completed in 1840. It is one of the earliest examples of a curvilinear cast iron glasshouses in the world. The Palm House consists of two wings, the cool wing and the tropical wing. Lanyon altered his original plans to increase the height of the latter wing's dome, allowing for much taller plants. In the past these have included an 11 metre tall globe spear lily. The lily, which is native to Australia, finally bloomed in 2005 after a 23-year wait. The Palm House also features a 400-year-old Xanthorrhoea.References:
Kristiansten Fortress was built to protect the city against attack from the east. Construction was finished in 1685. General Johan Caspar von Cicignon, who was chief inspector of kuks fortifications, was responsible for the new town plan of Trondheim after the great fire of 18 April 1681. He also made the plans for the construction of Kristiansten Fortress.
The fortress was built during the period from 1682 to 1684 and strengthened to a complete defence fortification in 1691 by building an advanced post Kristiandsands bastion in the east and in 1695 with the now vanished Møllenberg skanse by the river Nidelven. These fortifications were encircled by a continuous palisade and thereby connected to the fortified city. In 1750 the fortress was modernized with new bastions and casemates to protect against mortar artillery.