Grosmont Castle

Castle Norman-era ruined castle with medieval defensive remains

Grosmont Castle in Monmouthshire remains a compact Norman ruin; visitors combine the keep and earthworks with countryside walks and nearby medieval villages.

Main image

Grosmont Castle is a medieval Norman stone castle in the village of Grosmont in Monmouthshire, Wales, with primary construction dating to the 12th century. It is historically associated with the group known as the Three Castles in this border region.

Visitors encounter visible masonry remnants of curtain walls and the inner ward rather than a complete keep; the site is a typical example of a frontier stronghold adapted and rebuilt in stone during the high Middle Ages. The castle later fell into decline and survives as a ruin reflecting its medieval defensive role.

The castle stands within the village of Grosmont in southeast Wales, in the historic marcher territory near Abergavenny and other medieval border fortifications.

  • Three Castles: Forms one of the medieval 'Three Castles' of the Welsh Marches together with Skenfrith and White Castle
  • Surviving structures: Ruined remains include curtain walls, a surviving keep footprint and a defended inner enclosure dating mostly from the 12th century
Grosmont Castle
Grosmont, Monmouthshire, Wales
51.9154, -2.8660
Free

How to Get to Grosmont Castle #

Grosmont village is in northwest Monmouthshire. By car it is reachable from Abergavenny (roughly 20-30 minutes) via local B-roads; parking is typically on village lanes or small lay-bys near the castle. Public transport is limited - visitors should check local bus timetables to Abergavenny or Hereford and plan a taxi or a longer walk to the village.

Tips for Visiting Grosmont Castle #

  • Visit early morning to enjoy the quiet of the ruin before local walkers and dog-walkers arrive.
  • Look for information panels in the village - they place the castle within the story of the Three Castles of Monmouthshire (Grosmont, Skenfrith and White Castle).
  • Stop at the village pub or the church opposite the castle - both are part of the day's history and make good spots to read the landscape.

Best Time to Visit Grosmont Castle #

Late spring through early autumn provides the best weather for seeing the castle and wandering local lanes.

Summer
June-August · 12-20°C
Warmest and sunniest months for exploring the ruin and surrounding lanes.
Spring-Autumn
April-May, September-October · 8-15°C
Pleasant for walks with fewer visitors; spring brings wildflowers in hedgerows, autumn brings crisp light.

Weather & Climate near Grosmont Castle #

Climate

Grosmont Castle's climate is classified as Oceanic - Oceanic climate with mild summers (peaking in July) and cold winters (coldest in February). Temperatures range from 2°C to 20°C. Moderate rainfall (788 mm/year).

Air Quality: AQI 33 Good
Best Time to Visit
JulyMayJune
Temperature & Rainfall
Temperature Range
31°
Warmest Month
-11°
Coldest Month
Monthly Conditions

January

January is cold with highs of 7°C and lows of 2°C. The wettest month with 87 mm of rain and mostly overcast skies.

42 Poor

Comfort

Feels Like Cold
C
Temperature
96%
Humidity
Very Humid

Weather

87 mm
Rainfall
3.6 m/s
Wind
Light Breeze
0.1
UV Index
Low
8.2h daylight

February

February is the coolest month with highs of 7°C and lows of 2°C. Moderate rainfall (61 mm) and mostly overcast skies.

44 Poor

Comfort

Feels Like Cold
C
Temperature
94%
Humidity
Very Humid

Weather

61 mm
Rainfall
3.6 m/s
Wind
Light Breeze
0.1
UV Index
Low
9.8h daylight

March

March is cold with highs of 9°C and lows of 3°C. Moderate rainfall (63 mm) and mostly overcast skies.

54 Acceptable

Comfort

Feels Like Cold
C
Temperature
91%
Humidity
Very Humid

Weather

63 mm
Rainfall
3.7 m/s
Wind
Light Breeze
0.4
UV Index
Low
11.7h daylight

April

April is cold with highs of 12°C and lows of 4°C. Moderate rainfall (55 mm) and mostly overcast skies.

56 Acceptable

Comfort

Feels Like Cold
C
Temperature
12°
86%
Humidity
Very Humid

Weather

55 mm
Rainfall
3.3 m/s
Wind
Light Breeze
0.8
UV Index
Moderate
13.7h daylight

May

May is cool with highs of 16°C and lows of 7°C. Moderate rainfall (54 mm) and mostly overcast skies.

66 Good

Comfort

11°
Feels Like Cool
11°C
Temperature
16°
84%
Humidity
Very Humid

Weather

54 mm
Rainfall
3.2 m/s
Wind
Light Breeze
1.1
UV Index
High
15.4h daylight

June

June is cool with highs of 18°C and lows of 10°C. Moderate rainfall (56 mm) and mostly overcast skies.

66 Good

Comfort

14°
Feels Like Cool
14°C
Temperature
10° 18°
84%
Humidity
Very Humid

Weather

56 mm
Rainfall
3.0 m/s
Wind
Light Breeze
1.4
UV Index
High
16.3h daylight

July

July is cool with highs of 20°C and lows of 12°C. Moderate rainfall (42 mm) and mostly overcast skies.

69 Good

Comfort

16°
Feels Like Cool
16°C
Temperature
12° 21°
84%
Humidity
Very Humid

Weather

42 mm
Rainfall
2.9 m/s
Wind
Calm
1.3
UV Index
High
15.9h daylight

August

August is cool with highs of 20°C and lows of 12°C. Moderate rainfall (64 mm) and mostly overcast skies.

65 Good

Comfort

16°
Feels Like Cool
16°C
Temperature
12° 20°
86%
Humidity
Very Humid

Weather

64 mm
Rainfall
2.7 m/s
Wind
Calm
1.0
UV Index
High
14.4h daylight

September

September is cool with highs of 17°C and lows of 10°C. Moderate rainfall (70 mm) and mostly overcast skies.

63 Good

Comfort

14°
Feels Like Cool
14°C
Temperature
10° 17°
88%
Humidity
Very Humid

Weather

70 mm
Rainfall
2.7 m/s
Wind
Calm
0.7
UV Index
Moderate
12.5h daylight

October

October is cool with highs of 14°C and lows of 7°C. Moderate rainfall (74 mm) and mostly overcast skies.

55 Acceptable

Comfort

11°
Feels Like Cool
11°C
Temperature
14°
92%
Humidity
Very Humid

Weather

74 mm
Rainfall
2.9 m/s
Wind
Calm
0.3
UV Index
Low
10.5h daylight

November

November is cold with highs of 10°C and lows of 4°C. Moderate rainfall (77 mm) and mostly overcast skies.

51 Acceptable

Comfort

Feels Like Cold
C
Temperature
10°
95%
Humidity
Very Humid

Weather

77 mm
Rainfall
2.9 m/s
Wind
Calm
0.1
UV Index
Low
8.7h daylight

December

December is cold with highs of 8°C and lows of 3°C. Regular rainfall (85 mm) and mostly overcast skies.

44 Poor

Comfort

Feels Like Cold
C
Temperature
96%
Humidity
Very Humid

Weather

85 mm
Rainfall
3.3 m/s
Wind
Light Breeze
0.0
UV Index
Low
7.7h daylight

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