Here is a list which i found quite interesting and probably like a lot of people didn't realise existed

Name Elevation Location Last eruption
meters feet Coordinates
Ardnamurchan - - 56°44′00″N 5°59′00″W c.55 million years ago
Arthur's Seat 251 824 55°56′39″N 3°09′43″W Carboniferous
Borrowdale Volcanics (Cumbria) - Silurian or earlier
Cheviot Hills 815 2674 - Ordovician
Cuillin Hills (on Isle of Skye) 57°12′N 6°12′W Tertiary
Dundee Law extinct volcano in Dundee 500 56°28′11″N 2°59′22″W Ordovician
Edinburgh Castle castle rock - - 55°56′55″N 3°12′03″W Lower Carboniferous
Giant's Causeway - - 55°15′00″N 6°29′07″W Paleogene
Glen Coe Caldera - - 56°40′08″N 5°01′34″W Silurian
Snowdonia mountains in North Wales Ordovician

It is a list of All the "Dormant" Volcanoes in Great Britain now dormant doest mean extinct just not active "Presently"............ Which might be closest to Oakham ...