# Castle G3 North Belfast. 545 people (mid-2024 estimate) in 0.1 square kilometres. Castle G3 had 559 usual residents at the census (NISRA Census 2021). In Castle G3, 100.0% of homes and businesses could get gigabit-capable broadband in January 2026. Neighbourhood. Code N20000809. In: [Northern Ireland](https://openindex.co.uk/northern-ireland) › [Belfast](https://openindex.co.uk/belfast) ## Key figures - **Population: 559** (2021). Castle G3 had 559 usual residents at the census (NISRA Census 2021). Joint 3,738th least populated of 46,844. Source: Census 2021, England and Wales and Scotland's Census 2022 and Census 2021, Northern Ireland, 2021. Published 21 July 2026. https://openindex.co.uk/belfast/neighbourhood/n20000809#f-population - **Gigabit broadband coverage: 100.0%** (January 2026). In Castle G3, 100.0% of homes and businesses could get gigabit-capable broadband in January 2026 (Ofcom). UK 87.8%. Source: Connected Nations (Ofcom), January 2026. Published 13 May 2026. https://openindex.co.uk/belfast/neighbourhood/n20000809#f-gigabit-coverage - **Aged 15 to 64: 59.6%** (2021). 59.6% of residents in Castle G3 were aged 15 to 64 at the census (NISRA Census 2021). Joint 11,931st lowest of 46,844. Source: Census 2021, England and Wales and Scotland's Census 2022 and Census 2021, Northern Ireland, 2021. Published 21 July 2026. https://openindex.co.uk/belfast/neighbourhood/n20000809#f-age-15-to-64 - **Aged 65 and over: 18.6%** (2021). 18.6% of residents in Castle G3 were aged 65 or over at the census (NISRA Census 2021). Joint 23,352nd highest of 46,844. Source: Census 2021, England and Wales and Scotland's Census 2022 and Census 2021, Northern Ireland, 2021. Published 21 July 2026. https://openindex.co.uk/belfast/neighbourhood/n20000809#f-age-65-and-over ## On the map - [Gigabit coverage by neighbourhood](https://openindex.co.uk/map/gigabit-broadband#place=N20000809) (Connected Nations (Ofcom) · January 2026): In Castle G3, 100.0% of homes and businesses could get gigabit-capable broadband in January 2026. - [Average house price by council](https://openindex.co.uk/map/house-prices#place=N20000809) (UK House Price Index · August 2026): Published for whole councils, so the map colours all of Belfast. The outline is Castle G3. - [Crime and ASB by neighbourhood](https://openindex.co.uk/map/recorded-crime#place=N20000809) (Police recorded crime and outcomes (data.police.uk) · August 2026): Police recorded 2 crimes and anti-social behaviour incidents in Castle G3 in August 2026. - [Population by neighbourhood](https://openindex.co.uk/map/population#place=N20000809) (Census 2021, England and Wales): Castle G3 had 559 usual residents at the census. Northern Ireland Multiple Deprivation Measure 2017 is published for the Super Output Areas (2001), whose boundaries differ from this neighbourhood’s, so it has no figure for Castle G3. [See deprivation across Belfast](https://openindex.co.uk/belfast/deprivation) ## How Castle G3 compares Each neighbourhood against every other neighbourhood the measure covers. | Measure | Castle G3 | Rank | Compared with | | --- | --- | --- | --- | | Population | 559 | 173rd most populated | 735 neighbourhoods, Belfast · 2021 | | Gigabit broadband coverage | 100.0% | joint highest | 735 neighbourhoods, Belfast · Jan 2026 | | Aged 15 to 64 | 59.6% | joint 94th lowest | 735 neighbourhoods, Belfast · 2021 | | Aged 65 and over | 18.6% | joint 214th highest | 735 neighbourhoods, Belfast · 2021 | ## What is the population of Castle G3? Castle G3 had 559 usual residents at the census. Castle G3 is the joint 3,738th least populated of 46,844 in the UK. ## Figures for the whole of Belfast These figures are published for the whole of Belfast, not for each neighbourhood, so they describe all of Belfast and not Castle G3 alone. [See Belfast](https://openindex.co.uk/belfast) - **Average house price: £184,768** (August 2026). Belfast’s average house price was £184,768 in August 2026 (HM Land Registry). Up 7.7% in a year. Source: UK House Price Index, August 2026. Published 21 October 2026. - **Population estimate: 351,927** (2025). Belfast’s population was an estimated 351,927 in mid-2025 (ONS population estimates). Down 0.1% in a year. Source: Mid-year population estimates, 2025. Published 1 October 2026. - **Female life expectancy: 80.5 years** (2022 to 2024). A baby girl born in Belfast could expect to live 80.5 years, based on deaths in 2022 to 2024 (ONS life expectancy). UK 83.0 years. Source: Life expectancy for local areas of the UK, 2022 to 2024. Published 10 December 2025. - **People in radon Affected Area squares: 14%** (2022). About 14% of people in Belfast live in a 1 km square that the radon atlas marks as a radon Affected Area. UK 44%. Source: Worked out by Open Index from the UKHSA and BGS radon atlas and census output areas. Published 1 December 2022. ## Castle G3 in brief Castle G3 had 559 usual residents at the census. In Castle G3, 100.0% of homes and businesses could get gigabit-capable broadband in January 2026. 59.6% of residents in Castle G3 were aged 15 to 64 at the census. 18.6% of residents in Castle G3 were aged 65 or over at the census. ## About - Type: Neighbourhood - Code: N20000809 - Middle area: [Castle G](https://openindex.co.uk/belfast/castle-g) - Ward: [Cavehill †](https://openindex.co.uk/belfast/ward/cavehill) - Constituency: [Belfast North †](https://openindex.co.uk/constituency/belfast-north) - Council: [Belfast](https://openindex.co.uk/belfast) - Nation: [Northern Ireland](https://openindex.co.uk/northern-ireland) - Area: 0.14 km² - People, mid-2024: 545 † Best fit: the ward and constituency this neighbourhood mostly lies in. Its edges do not follow theirs. ## Next door [Castle G1](https://openindex.co.uk/belfast/neighbourhood/n20000805), [Castle D1](https://openindex.co.uk/belfast/neighbourhood/n20000796), [Castle J1](https://openindex.co.uk/belfast/neighbourhood/n20000807), [Castle G5](https://openindex.co.uk/belfast/neighbourhood/n20000820), [Castle J4](https://openindex.co.uk/belfast/neighbourhood/n20000816), [Castle G4](https://openindex.co.uk/belfast/neighbourhood/n20000819) ## Latest updates for Castle G3 - August 2026 house prices published: HM Land Registry and partners · Oct 2026. - September 2026 rent published: ONS private rents · Oct 2026. - Nitrogen dioxide (NO2) updated: Defra · Oct 2026. - 2025 population published: ONS population estimates · Oct 2026. The same figures as JSON: https://openindex.co.uk/v1/places/N20000809 ## How to cite Source: Open Index, openindex.co.uk. Link to this page, https://openindex.co.uk/belfast/neighbourhood/n20000809, or to one figure with its anchor, https://openindex.co.uk/belfast/neighbourhood/n20000809#f-population. Open Index's own text and the figures it works out are licensed under CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Source data keeps its publishers' licences, named with each figure. Give each figure's period and source with it. Snapshot 2026.10.11. The HTML page: https://openindex.co.uk/belfast/neighbourhood/n20000809