2015:276 - Tower Hill, Howth, Dublin

A targeted test excavation was carried out at the suspected site of a motte castle (DU016-002001) in the vicinity of the Martello Tower (DU016-002001) on Tower Hill in Howth Co. Dublin  by the Resurrecting Monuments community archaeology group from 19 to 29 August 2015. The suspected motte is known from 18th-century cartographic and pictorial representation, most famously by Gabriel Beranger who depicted a large flat-topped mound surrounded by a circular bank on Tower hill in the 1770s.

The excavation was funded under the Irish Research Council’s ‘New Foundations Grant Scheme’ and the project was coordinated by Grassroots Archaeology in partnership with Professor Gabriel Cooney of UCD, supported by Fingal County Council. The works were carried out under ministerial consent. Excavation at Tower Hill sought to test a geophysical anomaly identified during the earlier stages of the project.

The geophysical survey of a grid 40m x 40m was conducted at the Tower Hill site in May 2015 by Kevin Barton of Landscape and Geophysical Services and the Resurrecting Monuments group to investigate potential subsurface features that may be associated with the suspected motte castle (DU016-002001). This survey identified a curvilinear anomaly which had the potential to represent a cut feature. It was thought that this feature could possibly have represented an enclosing defensive ditch surrounding the motte castle.

A trench 8m x 1.5m was excavated across the position of the curvilinear anomaly to ascertain its character, and extent. The trench was excavated by hand and all arising soil was passed through 30mm sieves. The topsoil (C01) was found to be an imported modern layer c. 0.4m deep representing recent landscaping at the site. This overlay a deposit of former garden soils thought to date to the early–mid 20th century during which time Tower Hill was in use as allotments. This deposit was c. 0.31m deep.

In the eastern portion of the trench, a compact layer of redeposited subsoil was observed. This compact and hard layer (C02) occurred close to the upstanding Martello Tower and may represent a working surface dating to the construction of the tower.

This layer overlay a deep deposit of mid-brown silty clay (C04) mixed through with patches of redeposited sandy boulder clay (C05). Contexts C04 and C05 contained ten sherds of medieval pottery including Dublin-type wares, Saintonge ware and Leinster Cooking Ware. In addition, these contexts contained post-medieval pottery ranging from north Devon wares to the dipped wares and transferprinted wares of the last decades of the 18th century. A copper alloy dress pin with a ball head, of 17th/18th-century date was also retrieved from C05. Contexts 4 and 5 were interpreted as a cultivated plough zone created late in the 18th century as a result of the levelling of the suspected motte mound and pre-dating the construction of the Martello tower at the beginning of the 19th century. The date of the pottery assemblage from contexts 4 and 5 supports this interpretation. No cut feature or ditch was identified in this trench.

Grassroots Archaeology, 15 Vartry Heights Roundwood, co. Wicklow