Glad to see that you are wearing gloves. I understand the sap causes blisters! They are impressive though.
Whenever I see them I sing the old Genesis song to myself. It is about the Victorian explorer who went off in search of the Giant Hogweed to bring it back to the UK. I wonder...
Sounds like it could be the big one. It can grow up to 5m tall with leaves up to 1m long. Sometimes red spotted stem. It does like dampish areas. It grows in some parts of Norfolk.
Warning it is a nasty beasty!! Do not get any of the sap on your hands.