Royal Marines selection and training
Royal Marines recruit training is the longest basic modern infantry training programme of any Commonwealth, or North Atlantic Treaty Organization (NATO) combat troops. The Royal Marines are the only part of the British Armed Forces where officers and other ranks are trained at the same location, the Commando Training Centre Royal Marines (CTCRM) at Lympstone, Devon.
Source: Wikipedia — Royal Marines selection and training (CC BY-SA 4.0)