Octagon buildings and structures are characterized by an octagonal plan form, whether a perfect geometric octagon or a regular eight-sided polygon with approximately equal sides.
The oldest known octagon-shaped building is the Tower of the Winds in Athens, Greece, which was constructed circa 300 B.C. Octagon houses were popularized in the United States in the mid-19th century and there are too many to list here, see instead List of octagon houses. There are also octagonal houses built in other times and cultures.
Below is a list of octagonal buildings and structures worldwide, excluding houses and windmills.
The office pods of Callam Offices in Canberra
Chinaman's Hat an octagonal gazebo-like structure in the South Channel of Port Phillip Bay, Victoria.
The Octagon Theatre at the University of Western Australia.
The old site of Hotel Saville in South Yarra, Melbourne, now unofficially referred to as The Blocktagon, which was renovated into a residential dwelling made up of six octagonal apartments during the eleventh season of reality show The Block.
At least 19 historic octagon houses are known to exist in Canada distributed across 4 eastern provinces. In Canada, the octagon house craze also engendered an octagonal deadhouse phenomenon. This included octagonal deadhouses, pre-burial edifices, built in the mid to late 1800s along Yonge Street in south-central Ontario, from just north of Toronto to Aurora. At least 3 octagon houses are classified as heritage sites, one in Richmond Hill and the other in King. Extant octagon houses in Canada include the following:
In New BrunswickPocologan, New Brunswick, octagon house
Sackville, New Brunswick, Captain George Anderson House, built in 1855, is a locally designated heritage site
In Nova ScotiaTatamagouche, Nova Scotia: Fraser Octagon House, built in 1857, provincially designated heritage site
In Ontario
In QuebecGuérin, Quebec octagon house
Other buildings and structures
Bastion Nanaimo, British Columbia
Chapel at Dundurn, Hamilton, Ontario
Miscou Island Lighthouse – strategic Baie des Chaleurs octagonal colonial lighthouse
Huron County Gaol – distinctive octagonal jail design, 1839–41
Pachena Point Light on Vancouver Island, British Columbia
Speedside United Church, in Centre Wellington, Ontario
Liaodi Pagoda, China
Lingxiao Pagoda, China
Also many other pagodas
Lighthouse of Alexandria
Pharos of Abusir
St. George's Cathedral, Addis Ababa
Palatine Chapel in Aachen
Tower of the Winds, Athens, Greece
Rumbach Street synagogue, Budapest
Ferdows Religious School, Toon
Jabalieh
Dome of the Rock, Jerusalem. 687-691 CE
The Baptistery (5th century), Albenga
Baptistery of San Giovanni, Florence
The Battistero or Baptistery of Parma
Basilica of San Vitale, Rome
Castel del Monte (Apulia), Andria (BT)
Church of St. Giacomo, Vicovaro
New Zealand
The Octagon, the former Trinity Congregational Church in Christchurch, New Zealand
Ankenes Church
Bardu Church
Buvik Church
Dolstad Church, mixed octagonal-cruciform
Klæbu Church
Røssvoll Church
Støren Church
Trinity Church (Oslo), octagonal-cruciform combined
Vinje Church (Hemne)
Alcazar of Jerez de la Frontera has an Octagonal Tower, in Almohad style
Hedvig Eleonora Church, Stockholm
Abbot's Kitchen, Glastonbury
Abbot's Kitchen, Oxford
Avenue Methodist Church in Sale, Greater Manchester
Dutch Cottage, Rayleigh, Essex
18th century replicas of the Athenian Tower of the Winds in the ornamental gardens of the following stately homes:
Mount Stewart
Shugborough Hall
West Wycombe Park
Naze tower, Walton on the Naze
Octagonal chapter houses at the following cathedrals:Liverpool Cathedral
Salisbury Cathedral
Truro Cathedral
Wells Cathedral
York Minster
Octagon Centre, Sheffield
Octagonal lantern tower, Ely Cathedral, Ely
Octagon Chapel, Norwich
Dreghorn & Springside Parish Church
St James Church, Teignmouth
Pagoda at Royal Botanic Gardens, Kew, London
Storm Tower at Compass Point, Bude, Cornwall
St. John’s Methodist Church, Arbroath
United Reformed Church in Cheadle Hulme
The main tower of Hadlow Castle, Kent
The Butter Market, Barnard Castle, County Durham
Hertford College's Middle Common Room, Oxford