highlights of the 10-day tour include arthur 's legendary birthplace , tintagel castle , on a rocky cliff above the atlantic ; the desolate dozmary pool , one of several spots where arthur is believed to have thrown his sword , excalibur , to be received by the lady of the lake ; stonehenge , said to have been transported by the wizard merlin from ireland ; the glastonbury tor , where legend has it that king melwas held queen guinevere captive until arthur rescued her ; and what is generally agreed to be king arthur 's grave , in glastonbury .