Wedding Travelling

Interesting drive into Ireland. Did my first driving in the UK. Rented a car and drove for 2.5 from Dublin airport (Republic of Ireland) to Tyrone County in Northern Ireland UK. Interesting as i was trying to decipher if i was in Northern Ireland or the Republic as the speed limit sign kept changing from KM/Hr to Miles/hr and vice versa. Had to apply a bit of common sense and quick mental sums to gadge the speed limit of my driving.