Gaer (Black Mountains)

Coed-y-Cerrig National Nature Reserve is located at the bottom of a deep valley in the Black Mountains, about 3.7 miles (6.0 km) north of Abergavenny and 2 miles (3.2 km) west of Llanfihangel Crucorney in Wales. Despite its small size, the reserve has a variety of wet and dry woodland habitats, making it rich in wildlife. Its moist valley floor is covered by an unusual type of alder woodland rich in fungi in the autumn.

Cwmyoy is an extensive rural parish in Monmouthshire, Wales (Welsh: Cwm Iou, for the valley and parish; Welsh: Cwm-iou, for the village). The standard Welsh name is Cwm Iau or Cwm-iau. In the Gwentian dialect of Welsh that was spoken here until the late 1800s, the name was pronounced as Cwm Iou ('ou', also spelt informally 'oi', for standard 'au' is a common feature of south Wales Welsh). The 'English' name is in fact this local dialect form in a more English spelling. The name of the valley probably originates from the Welsh word iau meaning yoke, in reference to the shape of the hill surrounding it.The village of Cwmyoy is 7 miles (11 km) north of Abergavenny and 4 miles (6.4 km) south of Llanthony in the Vale of Ewyas in the Black Mountains. It is within the Brecon Beacons National Park, in an upland location just below the broad ridge of Hatterrall Hill, which carries the Wales–England border and Offa's Dyke Path.

The Church of St Martin, Cwmyoy, Monmouthshire, Wales, was begun in the 12th century, although most of the current structure dates from the 13th century. The church is most notable for its extreme tilt, the result of a landslide. This has led to many attempts to strengthen the church and prevent its collapse, through the use of massive tie beams and buttresses. The church is in the Gothic style, and has a chancel, nave, south porch, and western tower. A round-headed north window dates to the 12th century, and the nave roof has been dated to the late 13th or early 14th century. St Martin's is a Grade I listed building and an active parish church. It is dedicated to St Martin of Tours.

The Tabernacle Baptist Chapel, Ffwthog, near Cwmyoy, Monmouthshire is a Baptist chapel, with attached manse, dating from 1837. Largely unaltered externally and internally, the chapel is a Grade II* listed building.

Crucorney Welsh: Crucornau is a community in the county of Monmouthshire, Wales. It is the northernmost community in the county and covers the villages of Llanvihangel Crucorney, Pandy, Cwmyoy and Llanthony amongst others. The Vale of Ewyas comprises much of the northern part of the community, with the River Honddu running through Llanthony and Llanvihangel Crucorney, before turning northeast passing Pandy towards the River Monnow. The 2011 population was 1,201.Notable landmarks include Llanthony Priory, a Grade I listed former Augustinian priory at Llanthony. Offa's Dyke Path runs along the border between Crucorney and the English county of Herefordshire. The community also has a voluntary group, The Crucorney Environmental Group, which oversees environmental and sustainability issues, including sustainable development, recycling and litter picking.

Ty-mawr Farmhouse, Ffwthog, Cwmyoy, Monmouthshire, is a farmhouse dating from the early 16th century, which was extended in the 17th century and then reduced in size in the 18th century. The farmhouse is a Grade II* listed building, with its range of barns and its bee shelter having separate Grade II listed building designations.

Partrishow, also known as Patricio, Patrishow, or by its Welsh names Merthyr Isw and Llanisw, is a small village and historic parish in the county of Powys (historically Brecknockshire), close to its border with Monmouthshire. It is in the valley of the Grwyne Fawr, in the Black Mountains of South Wales, within the Brecon Beacons National Park.

The Church of St Issui, Partrishow, Powys, Wales, is a Grade I listed parish church dating from 1060. The existing building was mainly constructed in the 14th and 15th centuries and was sensitively restored in 1908–1909. The church is most famous for its rood screen which dates from 1500. It is a Grade I listed building.

Ty-Hwnt-y-Bwlch Farmhouse, (Welsh: translation - The house near the pass), Cwmyoy, Monmouthshire is a farmhouse in the north of the county dating from the late 16th century. Located on the hillside above the Church of St Martin, it is a Grade II* listed building.

Llwyn-celyn Farmhouse, Llanvihangel Crucorney, Monmouthshire is a farmhouse of late medieval origins. It is a Grade I listed building.

Bryn Arw is a hill in the Black Mountains of the Brecon Beacons National Park in Monmouthshire, south Wales. It lies 4 km north of the town of Abergavenny and 1.5 miles west of the village of Llanvihangel Crucorney. Its summit at 384m (1260 feet) above sea level is the more northerly of two tops which lie on the crest of a slightly arcuate north-south ridge which drops away to the south at first gently and then sharply. The hill is isolated from the main mass of the range by the valleys of Cwm Coed-y-cerig to the north and by Cwm Brynarw to the west. It is a Marilyn.

Pen y Clawdd Castle is a ditched mound with a double moat, roughly circular in shape, with a diameter of approximately 28m to 30m and about 2.4m high. The castle is in Llanvihangel Crucorney, about five miles to the north of Abergavenny, Monmouthshire, in south east Wales and lies between the Usk and Monnow rivers. The mound was designated a scheduled monument in 1950 and described as a defensive medieval motte.