PASSPORTS AND VISAS
While citizens of EU countries can now travel, in theory at least, freely between member states, you will require photo ID to travel by air anywhere outside of the UK, and a passport is the most recognised form of identification. The UK also operates border controls to everybody entering the UK (even from other EU states) and so a passport is therefore recommended for all trips outside of the UK.
Citizens of Australia, Canada, New Zealand and the USA generally do not require visas for short holiday visits to most European Countries, but if you are not a British (or EU) Citizen you should contact the nearest embassy of the relevant country to confirm entry requirements. Note also that Visa requirements can change, sometimes without any announcement or at very short notice.