Ancient Monuments

History on the Ground

This site is entirely user-supported. See how you can help.

Iron Age territorial boundary known as Beech Bottom Dyke

A Scheduled Monument in Marshalswick South, Hertfordshire

We don't have any photos of this monument yet. Why don't you be the first to send us one?

Upload Photo »

Approximate Location Map
Large Map »

If Google Street View is available, the image is from the best available vantage point looking, if possible, towards the location of the monument. Where it is not available, the satellite view is shown instead.


Latitude: 51.7688 / 51°46'7"N

Longitude: -0.3274 / 0°19'38"W

OS Eastings: 515510.18434

OS Northings: 209113.798157

OS Grid: TL155091

Mapcode National: GBR H84.21F

Mapcode Global: VHGPJ.8SRX

Entry Name: Iron Age territorial boundary known as Beech Bottom Dyke

Scheduled Date: 9 October 1981

Last Amended: 6 October 2000

Source: Historic England

Source ID: 1019136

English Heritage Legacy ID: 29449

County: Hertfordshire

Electoral Ward/Division: Marshalswick South

Built-Up Area: St Albans

Traditional County: Hertfordshire

Lieutenancy Area (Ceremonial County): Hertfordshire

Church of England Parish: St Albans St Saviour

Church of England Diocese: St.Albans


The monument includes a substantial late Iron Age boundary ditch, or dyke,
situated on the eastern outskirts of St Albans, extending some 1.4km to the
north east and 250m to the west of the junction of Beech Road and Harpenden
Road and lies within three areas of protection.

To the east of the road junction the Dyke ascends a slight valley for about
700m towards the point where its alignment is crossed by Valley Road. The
ditch here measures 30m-35m in width and up to 10m in depth, with steep sides
descending to a narrow flattened area of accumulated soil across the base.
Sections of the banks which originally flanked either side of the ditch can
still be seen along the northern edge of the ditch to the rear of the
properties on Old Harpenden Road and extending some 150m westwards from Valley
Road along the southern side of the Dyke. This latter section of bank may have
widened at a later date to form a cart track leading to a small quarry
alongside the southern scarp of the ditch. A narrow causeway, thought to have
been formed from quarry upcast, crosses the Dyke at this point.

Valley Road crosses the Dyke on a raised causeway which has effectively sealed
the ditch and earlier deposits in the base. This buried section is included in
the scheduling. The section of the Dyke between Valley Road and the railway
line (300m to the north east) is particularly well preserved. This section of
the ditch measures 20m-25m in width, 5m in depth and is flanked by largely
uninterrupted banks on both sides. The southern bank averages 5m in width and
1.5m in height, slightly larger than the northern bank which retains remnants
of a post-medieval hornbeam hedgerow. The ditch and the northern bank remain
visible for a further 80m to the east of the railway embankment, and the
infilled line of the ditch (a slight depression defined by upstanding sections
of the bank) continues eastwards towards the driveway to The Glen. To the east
of the driveway, in the grounds of No 144 and Nos 142-142e St Albans Road, the
ditch reappears as a substantial depression flanked by the northern bank.

Further east the ditch runs within the rear property boundaries of Nos 138 to
128 St Albans Road and is largely infilled. The extent of the buried feature
is known from earlier maps, and it can still be detected as a very slight
depression in the garden of No 130.

Archaeological observations of sewer trenches dug in 1932 demonstrated that
the Dyke continued some 400m south west beyond the Beech Road-Harpenden Road
junction. On the evidence of a hoard of Roman coins found some 3m above the
base of the ditch, this section appears to have become partly infilled by the
2nd century AD. The northern edge of the ditch is still visible, measuring up
to 1.8m in height and extending westwards for about 250m along the southern
verge of Batchwood Drive. A substantial part of the infilled ditch remains
largely undisturbed between the carriage way and the properties to the south
of Batchwood Drive and is included in the scheduling.

The Dyke is thought to have been constructed in the late pre-Roman Iron Age,
the period from the mid 1st century BC to the Roman invasion of AD 43. It lies
between two well known Iron Age settlements: Verlamion (the name given to
pre-Roman Verulamium known from coins minted on the site in the Late Iron
Age), across the valley of the River Ver to the west, and Wheathampstead on
the River Lea some 4km to the north east. Both settlements were also partly
enclosed by earthworks: Devil's Dyke and Wheeler's Ditch around Verlamion, and
The Moat, The Slad and a separate Devil's Dyke surrounding Wheathampstead. It
has been suggested that the Beech Bottom Dyke formed a link between the two
settlements and formed part of a territorial boundary isolating the high
ground to the south between the Rivers Ver and Lea. The Dyke terminates some
3.5km short of Wheathampstead, however the St Albans-Sandridge Road continues
on the same alignment and may prove to perpetuate the line of a less
substantial variant of the boundary.

In addition to the Valley Road causeway the following items are excluded from
the scheduling; all fences and walls, the surfaces of all modern roads, paths,
yards and driveways; all lamp posts and drain covers and all workshop and
garden buildings. The ground beneath all these items is, however, included.

The site of the monument is shown on the attached map extract.

Source: Historic England

Reasons for Scheduling

The Iron Age territorial boundary known as Beech Bottom Dyke, forms a
major component of the late Iron Age landscape surrounding the important
nucleated settlements near St Albans (Verlamion) and Wheathampstead.
Verlamion is located on the western bank of the River Ver, within and to the
south of Prae Wood and beneath and to the north of the later Roman town of
Verulamium. Excavations have shown the site to have been the trading and
administrative centre for the Catuvellauni, the most powerful tribe in south
eastern England prior to the Roman Conquest. The Wheathampstead settlement is
considered to have been a possible precursor to Verlamion and later a
satellite of the main centre, perhaps serving as a place of refuge and
defence, although defence may have become less important as the Catuvellauni
extended and consolidated their territory in the early first century AD.
Beech Bottom Dyke, possibly in association with other less durable markers, is
thought to have defined the boundary of a substantial estate, perhaps that
which supported the domestic economy of the tribal centre or its most
prominent inhabitants. Given its impressive dimensions, the Dyke must have
served as a considerable symbol of authority, and it will provide significant
insights into the nature of the society by whom it was constructed. The lower
profile of the ditch remains buried by accumulated silts and together with the
banks will retain valuable evidence relating to the manner and date of the
Dyke's construction. Soils sealed beneath the banks will contain evidence
illustrating the appearance of the surrounding landscape prior to the
construction of the Dyke, and the basal silts in the ditch may provide
environmental evidence for changes effecting this landscape alongside the
development of the Roman town of Verulamium.

Source: Historic England


Books and journals
Saunders, C, Havercroft, A B, 'Hertfordshire Archaeological Journal' in Excavations on the Line of the Wheathampstead By-pass 1974-77, , Vol. 8, (1982), 31-39
Wheeler, R E M, Wheeler, T V, 'Society of Antiquaries of London Research Report' in Verulamium: A Belgic and Two Roman Cities, , Vol. XI, (1936)
Title: Herts XXXIV NE
Source Date: 1925
6 inch edition

Source: Historic England

Other nearby scheduled monuments is an independent online resource and is not associated with any government department. All government data published here is used under licence. Please do not contact for any queries related to any individual ancient or schedued monument, planning permission related to scheduled monuments or the scheduling process itself. is a Good Stuff website.