Derwent Water, or sometimes called Derwent Lake and Bassenthwaite Lake was one single lake. The large alluvial flat (soil or sediments deposited by a river or other running water) of today has been formed by material deposited by both the River Greta and Newlands Beck. As the ice spread out over the wider valley, today this is what is known as Derwent Water, it slowed down leaving several dumlins (soil or sediments deposited by a river or other running water) which later, when partly drowned became islands.
Derwent Water is one and a half miles wide, approximately three miles long and between 70 to 80 feet deep. This is the widest lake in England. Because this lake is so shallow it can freeze over, apparently in 1969 the depth of the ice on the lake was eighteen inches thick. The Derwent river runs through Derwent Water, out of the lake near Portinscale village, through Bassenthwaite lake, into Cockermouth, Workington and then into the sea, this is a distance of approximately 30 miles.
There are four large islands on this lake of which only one has a building on it, this is Derwent Island. St Herberts Island is the largest island and this is right in the middle of the lake. Lords Island is where the Earl of Derwentwater used to live in a fine house with a drawbridge across to the mainland. This house, however, was neglected after the Earl moved away. This neglected house was pulled down and the stone was moved to Keswick where it was used to make a meeting hall, this is known as Moot Hall which still stands today in the middle of the market square. The last island is called Rampsholme Island, it was named after the wild garlic that grows on it. Ramsens is the proper name for wild garlic and in America it is called ramps. Hence where the name Rampsholme Island came from. The islands can be seen better from boat trips provided by the Keswick Launch Company.