Milecastle 45

Alloa Lea Quarry Cave is a short cave in the Five Yard Limestone of the Alston Block in Northumberland, England. It is situated in an old quarry on the road between Alloa Lea and Walltown. The total length of the cave is 10m.

Northumbria was an early medieval English kingdom, existing between 654 and 1066 AD, at its height spanning modern-day Northern England and Southern Scotland. The name derives from the Old English Norþhymbre meaning "the people or province north of the Humber", as opposed to the people south of the Humber Estuary. What was to become Northumbria started as two kingdoms, Deira in the south and Bernicia in the north. Conflict in the first half of the seventh century ended with the murder of the last king of Deira in 651, and Northumbria was thereafter unified under Bernician kings. At its height, the kingdom extended from the Humber, Peak District and the River Mersey on the south to the Firth of Forth on the north. Northumbria ceased to be an independent kingdom in the mid-tenth century when Deira was conquered by the Danes and formed into the Kingdom of York. The rump Earldom of Bamburgh maintained control of Bernicia for a period of time; however, the area north of the Tweed was eventually absorbed into the medieval Kingdom of Scotland while the portion south of the Tweed was absorbed into the Kingdom of England as the county of Northumberland and County Palatine of Durham.

Allolee to Walltown is the name given to a Site of Special Scientific Interest (SSSI) in Northumberland, England. The site, which follows the path of a section of Hadrian's Wall, is notable for an unusually wide range of grassland types growing on thin soil above the Whin Sill, a rock formation peculiar to the Northern Pennines.

Milecastle 44 (Allolee) was a milecastle on Hadrian's Wall (grid reference NY68886694).

Greenhead is a village and civil parish in Northumberland, England. The village is on the Military Road (B6318), about 17 miles (27 km) from Chollerford, 3 miles (5 km) from Haltwhistle and 9 miles (14 km) from Brampton, Cumbria along the A69 road. The A69 bypasses the village, but until the 1980s all vehicular traffic passed through it. The village lies just outside the Northumberland National Park, close to Hadrian's Wall. Just to the north of the village is the 12th-century Thirlwall Castle, recently restored and opened to the public. Nearby villages include Upper Denton and Haltwhistle. A former Methodist chapel in the village is now a youth hostel. The Pennine Way, the UK's first National Trail, passes through Greenhead.

Magnis or Magna was a Roman fort near Hadrian's Wall in northern Britain. Its ruins are now known as Carvoran Roman Fort and are located near Carvoran, Northumberland, in northern England. It was built on the Stanegate frontier and Roman road, linking Coria (Corbridge) in the east to Luguvalium (Carlisle) in the west, before the building of Hadrian's Wall. The fort is now the site of the Roman Army Museum.

Milecastle 46 (Carvoran) was a milecastle on Hadrian's Wall (grid reference NY66466601).

Blenkinsop Hall (grid reference NY68186412) is a privately owned, castellated 19th-century country house situated on the banks of the Tipalt Burn near Greenhead, Northumberland. The legal address of the property is Haltwhistle, Northumberland, NE49 9LY. It is a Grade II listed building, reflecting its historical and architectural significance. The property is located near Blenkinsopp Castle, which is primarily a ruin; both the Hall and the castle were owned by the same family for several generations.

Thirlwall Castle is a 12th-century castle in Northumberland, England, on the bank of the River Tipalt close to the village of Greenhead and approximately 20 miles (32 km) west of Hexham. It was built in the 12th century, and later strengthened using stones from nearby Hadrian's Wall, but began to fall into disrepair in the 17th century. The site is protected by Grade I listed building and Scheduled Ancient Monument status.

Blenkinsopp Castle (spelled Blenkinsop in many records) is a fire-damaged, partly demolished 19th-century country mansion, incorporating the ruinous remains of a 14th-century tower house, which is located above the Tipalt Burn approximately one mile south of Greenhead, Northumberland, England. It is a Grade II listed building; it is also a Scheduled Ancient Monument as one of the "surviving tower houses retaining significant medieval remains".

Greenhead was a former railway station, which served the village of Greenhead, Northumberland in Northumberland between 1836 and 1967.

Milecastle 43 (Great Chesters) was a milecastle on Hadrian's Wall (grid reference NY70356684). It was obliterated when the fort at Great Chesters (Aesica) was built.