Just Googled a few of these - please add any more!
Hunstanton Norfolk
Wrong: Hun-stan-ton
Right: Hun-ston
Bedworth Warwickshire
Wrong: Bed-worth
Right: Bed-uth
Wales
Wrong: Lan-dud-no
Right: Clan-did-no
Oxford (Magdalen college)
Wrong: Mag-de-lain
Right: Maud-lin
Dumfries and Galloway
Wrong: Kir-cud-bright
Right: Kir-koo-bree
Leominster (Herefordshire)
Wrong: Lee-o-min-ster
Right: Lem-ster
Alnwick(Northumberland)
Wrong: Aln-wik
Right: An-ik
Prudhoe (Northumberland)
Wrong: Prud-hoe
Right: Prud-a
Godmanchester (Cambridgeshire)
Wrong: God-man-ches-ter
Right: Gum-ster
Cholmondeley (Cheshire)
Wrong: Chol-mon-de-lee
Right: Chum-lee