River TamarThe Tamar is a river bordering the English counties of Devon and Cornwall. At its mouth, the Tamar flows into the Hamoaze where it joins with the Lynher and the St Germans River before entering Plymouth Sound.
The Tamar is remarkable in that it flows southwards from a source which is less than 4 miles (6 km) from the north Cornish coast. From near this point the Cornish border heads to the sea along Marsland Water, making Cornwall nearly an island. However, in a few places the administrative border deviates from the river, leaving, for instance, the Devon village of Bridgerule on the 'Cornish' side. And for most of its length the river does not in fact form much of an obstacle to communication, there being some 20 road crossings.
The River Tamar in Tasmania was named after the Tamar in Cornwall.