Boxing Day (26th of December) is a public holiday.
Guy Fawkes night is celebrated on the 5th of November, with fireworks and bonfires.
A 2:
There are also other customs related to the UK that aren't really practicsed anywhere else, such as, Morris dancing, chasing cheese down a hill (it does really exist). Along with that there are also more people who visit the highlands in Scotland to try to spot the loch ness monster