Disclaimer: As an affiliate I may earn a commission on any qualifying purchase at no extra cost to you – read more.

Today Beaumaris is known as one of the greatest Welsh Castles that was never finished. Despite this, it still has an impressive history and holds within its crumbling walls many secrets which illuminate the history of North Wales and beyond. 

Here are 8 interesting facts about the castle, check out our full guide to the history of Beaumaris Castle to learn more.

1. It Cost £15,000 To Build (a lot in 1295)

When the castle was constructed in 1295, 2,000 men travelled to the site to work as builders. The total spent on the construction of the structure was £15,000. This was an extortionate amount. The income of the English treasury was less than £20,0001 (source: Wikipedia).


2. ‘Beaumaris’ Means Fair Marsh

The name Beaumaris comes from the Norman ‘beau marais’ which means ‘fair marsh.’ It must come from the description of the site that King Edward I of England chose for the Castle. 


3. It’s a Perfectly Symmetrical Design

As well as its size, the castle is known for its near-perfect symmetrical design. You only get a true feel for this when you see the castle from above as shown in this photo.

The design includes four concentric rings with a moat around the outside, this is said to make it ‘impenetrable’2 (source: CADW).

© Crown copyright (2022) Cymru Wales

4. The Castle Was Captured By Owain Glyndwr

Despite it’s ‘impenetrable design’, in 1403 the Castle was taken by the Welsh rebel Owain Glyndwr and his army. Unfortunately for them, it was soon recaptured by the English in 1045. 

It was again involved in conflict during the English Civil War in 1642. The Castle was originally held by royalists, who were loyal to the king, Charles I, however, in 1646 they were forced to surrender to the Parliamentary army3 (source: Visit Anglesey).


5. It’s Known as ‘The Greatest Castle Never Built’

Despite being hundreds of years old, Beaumaris was never completely finished. This is mainly because of its staggering size which meant it took a long time and a lot of money to construct. Construction was also hindered by a conflict with Scotland which drew Edward I’s attention away from the building work. 


6. Beaumaris is One of the ‘Iron Ring’ Castles

The ‘Iron Ring’ castles are a collection of Castles built by the English king, Edward I in an attempt to fortify and control North Wales. Most of these Castles were built by Edward’s architect, James of St George. Prior to Beaumaris, the pair had already constructed Conwy, Caernarfon and Harlech Castle. 


7. Townspeople Were Evicted to Make Room For the Castle

Before the Castle was built, on the site where it stands today, there was once a village called Llanfaes. The village cropped up in the 13th century and by the 1280s it was a bustling port town which played an essential role in trade between other port towns in Britain. 

Edward I, like the townspeople who had made the village their home, recognised the importance of the site. His troops began to demolish the town in 1295 and in response, the villagers petitioned the king but nothing was done.

When Edward died in 1307, most of the townspeople had been moved against their will to a new town 13 miles away that became Newborough4 (source: CADW).


8. It’s a UNESCO World Heritage Site

In the 1980s, Beaumaris was made a UNESCO Heritage Site. This means that it has been considered one of the world’s most significant sites and is deemed to be a site of ‘outstanding value to humanity.’5 (source: UNESCO).

If you’re interested in seeing the castle for yourself, see our full Beaumaris Castle visitors guide to find out exactly what’s inside today and whether it’s worth it.

Molly is Wales Guidebook's expert on castles. She has a master's degree in history and studied at Swansea University where she learnt about Welsh history and it's many castles. Molly loves to get out and explore historical buildings in person, with Oystermouth, Cardiff, and Caerphilly Castles among her favourites. When not geeking out on castles, Molly likes to spend her time reading, exploring the countryside or in the gym.