An Ivatt 2-6-2T crossing into Cornwallwith a Callington trainOpened in 1908 this fine single track bridge 120 feet above the River Tamar here at Calstock enables passengers today to still travel from Plymouth to Gunnislake , a journey of some fifteen miles taking no less than forty five minutes with a reversal necessary at Bere Alston. Services from Plymouth to as far as Gunnislake were retained despite closure plans in 1966 although the extension through to Callington was not saved. The Tamar Valley in this area was an important site for the mining of arsenic , tin , lead and especially copper which before the railway came in 1872 was carried down the Tamar to the port of Plymouth by boat , and the historic little port of Morwhellam Quay is today a popular heritage centre.