Dinorwic Slate Quarry is located close to the villages of Llanberis and Dinorwig in North Wales. It was at one time the second largest slate quarry in the world. It was quarried for more than 200 years, leaving terraces to a height of over 600 metres high, and at its peak it employed over 3000 people. Before the arrival of modern transport, quarrymen traveled on foot from as far afield as Anglesey each week, crossing the Menai Straits, or walking up from Caernarfon on a Sunday evening and staying in the quarry barracks until Saturday lunchtime, when they returned to their families and communities for only 24 hours before starting their return journey to work. Commercial quarry operations at Dinorwig started in 1787 although it didn’t start to flourish until the mid 1820s when a horse drawn tramway was constructed to Port Dinorwic. By the late 19th Century the quarry was employing over 3000 men and producing 100,000 tonnes slate products (mostly roofing slate) each year. The quarry continued in production until 1966 when a major slate waste heap collapse into a working area of the quarry halted production, after that slate was only produced sporadically until the quarry finally closed in 1969.