Castell Henllys

{{Use dmy dates|date=April 2022}}

{{Infobox museum

|name = Castell Henllys Iron Age Fort

|image = Castell Henllys - geograph.org.uk - 67364.jpg

|imagesize = 240px

|caption =

|map_type = Wales

|map_caption = Location within Wales

|coordinates = {{coord|52.017|-4.745|display=inline,title}}

|established =

|dissolved =

|location =

|type = Archaeological open-air museum

|visitors =

|director =

|curator =

|publictransit =

|website = [https://www.castellhenllys.com/ Castell Henllys]

}}

Castell Henllys (Welsh, "castle of the old court") is an archaeological site near Nevern in north Pembrokeshire, Wales.

The Iron Age hillfort has been the subject of an ongoing excavation since the start of the 21st century,{{cn|date=March 2025}} accompanied by an exercise in reconstruction archaeology whereby experiments in prehistoric farming have been practised. Four roundhouses and a granary have been reconstructed on their original Iron Age foundations – some 2,000 years old – the hillfort being the only site in Britain where this has been done.{{cite news|work=Tivyside Advertiser|date=5 July 2018|author=Dave Parkinson|title=Roundhouse built on site of existing Iron Age fort near Cardigan|url=http://www.tivysideadvertiser.co.uk/news/16334564.roundhouse-built-on-site-of-existing-iron-age-fort-near-cardigan/|accessdate=5 July 2018}} The Castell Henllys site includes significant earthworks and fortifications.{{Cite web|url=https://www.historic-uk.com/HistoryMagazine/DestinationsUK/Castell-Henllys-Iron-Age-Fort/|title=Castell Henllys Iron Age Fort|website=Historic UK}}

During the summer the site provides training for young archaeologists and is a popular visitor attraction.{{cite web|title=Visit Pembrokeshire: Castell Henllys Iron Age Fort|url=http://www.visitpembrokeshire.com/attractions-events/castell-henllys-iron-age-fort/|accessdate=4 April 2018}} It is owned by Pembrokeshire Coast National Park.