The TA's Medical Corps is taking over Astley Park in Chorley. The area will reverberate to the sound of enemy gunfire as its members evacuate a 'casualty' from a battlefield scene and provide emergency care in a field medical tent.
The Medical Corps hopes the demonstrations and information stands will encourage new members to sign up.
More top news
Breezy conditions continue for coasts & hills. Light rain developing from early Sunday morning but improving from the north through the day
Prime Minister Theresa May praised the "tremendous" work of the military as she visited Liverpool to mark Armed Forces Day.
The Prime Minister praised the armed forces as she joined celebrations in Liverpool.