Legend is, yet again, vague on where the lake was from which Excalibur came and eventually returned on the mortal wounding of King Arthur
Candidates for the Excalibur lake include
The Lily Ponds at Bosherston This lake is in the southwestern corner of Wales in the town of Bosherston, not far south of Pembroke.
Dozmary Pool Dozmary Pool is found in an atmospheric setting high on Bodmin Moor south of the Cornish town of Bolventor.
Llyn Llydaw This lake is in the Snowdonia National Park, in North Wales. It is only about ten miles from Llyn Ogwen.
Llyn Ogwen . Below the mountain of Tryfan is Llyn Ogwen, in Snowdonia National Park in northern Wales
Loe Pool Loe Pool is located south of the bayside town of Porthleven. This was not in fact a lake, it was an inlet of Mount's Bay until the thirteenth century
Pomparles Bridge Pomparles Bridge crosses the River Brue just south of the town of Glastonbury
Loch Arthur, Scotland Loch Arthur is just outside of the town of Beeswing, between the towns of Dumfries and Castle Douglas
Berth Pool The Berth and its pool are just outside the town of Baschurch in mid Wales.
Many of these are clearly unlike to have been the sort of lake where Excalibur could have been thrown - too small or too remote.
The Legend of King Arthur