It was from Church Bastion that King James II was fired upon as he approached the city on April 18th 1689, when the siege began in earnest. In the bastion you can see two demi-culverin cannon. Along the outer wall face is a small gateway, known as a ‘sallyport’. Tradition has it that this gateway was used during the siege leading into St Columb’s Cathedral.
Double Bastion occupies the south-west corner of the layout of the walls and, following removal of surrounding 19th-century housing in Nailor’s Row, is one of the most prominent parts of the monument and the site of one of the best known cannon known as ‘Roaring Meg’. The bastion is separated from the rampart walkway by a low stone plinth wall and, during the 19th century, was planted as a private garden.
New Gate Bastion: Two demi-culverin cannon are mounted on replicas of 17th-century field carriages. Four embrasures (openings) would have allowed artillery to provide covering fire along the adjacent wall face.
Royal Bastion is enclosed and contains the base of the Governor Walker memorial pillar, which was erected in 1826-8 to commemorate the shutting of the gates by ‘the brave thirteen Apprentice Boys of Derry’. It was damaged in an explosion in 1973.
Other bastions which have been removed/demolished:
Water Bastion: Most of this bastion was demolished around 1850 and all that now remains is a small platform. Outside the Millennium Forum theatre is a sculpture by the artist Antony Gormley.
From the Water Bastion, the rampart rises steeply, and this stretch terminates at a broad flight of steps giving access to Newmarket Street. It is the only place where the circuit of the walls is broken, and the opening was created in the 1860s to allow carts access to a new covered market. (Ruairí Ó Baoill, Island City, The Archaeology of Derry-Londonderry, p.140)
Coward’s Bastion:At the corner was the last of the bastions, removed during the first half of the 19th century. This area was attacked least during the 1689 siege and so was a popular posting for some members of the garrison, giving the bastion its name.
Gunner’s Bastion:Not far past Butcher’s Gate was a demi-bastion, known as the Gunner’s Bastion. It was removed sometime between 1843 and 1873.
Each bastion was given a name in 1622, in honour of the English settlers, such as “Lord Docwra’s Bulwark” or the Governer of the Plantation Bulwark”. During the 1689 Siege, the bastions took on more topical names given by the many refuges to the city, such as “Hangman’s Bastion” or “Coward’s Bastion”. The angled bastions were designed to give clear fields of fire along the whole length of the wall, so that there was no dead ground that could be exploited by an attacker.
https://thederrywalls.files.wordpress.com/2017/08/derry-walls-pdf.pdf
