The series concludes with an exploration of Co Mayo's textile industry, which has been subject to success, failure and now rejuvenation. Geographer Susan Hegarty explores the historical role of wool production, architect Orla Murphy looks at how the sector impacted on town planning in Westport, and engineer Tim Joyce investigates developments in woolen mill technology.

Tim Joyce explores the construction of the Boyne Viaduct in Drogheda, which is regarded as one of the finest examples of Victorian industrial engineering. Elsewhere, Orla Murphy explores a 21st century bridge over the river, and Susan Hegarty looks at 8,000 years of human settlement in the area.

Architect Orla Murphy investigates St John’s Cathedral and its gothic revival spire that dominates the skyline and represents the aspirations of 19th century Limerick. Geographer Susan Hegarty discovers the world famous qualities of the local blue limestone and Engineer Tim Joyce explores the city’s relationship with the Shannon.

Geographer Susan Hegarty investigates the mile-long quay wall and fascinating maritime history of Ireland's oldest city that has trade links with every corner of the world. Engineer Tim Joyce discovers the shipbuilding history of Waterford and Architect Orla Murphy explores the streets and building to uncover the history of the city and its people.

Architect Orla Murphy investigates the 19th century banking halls of Dame Street and the impact of personalities and politics on the architecture of the booming finance houses. Engineer Tim Joyce discovers how banking led to the innovative development of the docks and Geographer Susan Hegarty explores the role of bridges in planning the city.

Engineer Tim Joyce investigates how you bore an 800 metre tunnel through Goggins Hill and build a viaduct across Laune valley at the dawn of Ireland's railway age. Architect Orla Murphy explores the relationship of gunpowder with tunnel construction and Geographer Susan Hegarty discovers the markets and industries fuelling the railways.