Westminster is an area of central London within the City of Westminster on the north bank of the River Thames. Westminster's concentration of visitor attractions and historic landmarks, one of the highest in London, includes the Palace of Westminster, Buckingham Palace, Westminster Abbey and Westminster Cathedral. Westminster is a city in its own right, the twin to the ancient City of London further east and historically they jointly formed the focus of what is today regarded as London. The Palace of Westminster came to be the principal royal residence after the Norman Conquest of England in 1066, and later housed the developing Parliament and law courts of England

The city has long been known as a centre of education, particularly in the fields of medicine, Scots law, the sciences and engineering. The University of Edinburgh, founded in 1583 and now one of four in the city, was placed 17th in the QS World University Rankings in 2013 and 2014. The city is also famous for the Edinburgh International Festival and the Fringe, the latter being the largest annual international arts festival in the world. The city's historical and cultural attractions have made it the second most popular tourist destination in the United Kingdom after London, attracting over one million overseas visitors each year. Historic sites in Edinburgh include Edinburgh Castle, Holyrood Palace, the churches of St. Giles, Greyfriars and the Canongate, and the extensive Georgian New Town, built in the 18th century. Edinburgh's Old Town and New Town together are listed as a UNESCO World Heritage Site, which has been managed by Edinburgh World Heritage since 1999.

Dublin is the largest and capital city of Ireland. The English name is derived from the Irish name Dubh Linn, meaning "black pool". It is a primate city with an urban population of over 1 million, containing almost 25% of the country's population. Dublin is situated near the midpoint of Ireland's east coast, at the mouth of the River Liffey, and at the centre of the Dublin Region. The city is listed by the Globalization and World Cities Research Network (GaWC) as a global city, with a ranking of "Alpha-", placing it among the top thirty cities in the world. It is a historical and contemporary centre for education, the arts, administration, economy and industry.

Glasgow is the largest city in Scotland and third most populous in the United Kingdom. The city is situated on the River Clyde in the country's west central lowlands. A person from Glasgow is known as a Glaswegian. Glasgow grew from the medieval Bishopric of Glasgow and the later establishment of the University of Glasgow in the 15th century, which subsequently became a major centre of the Scottish Enlightenment in the 18th century. From the 18th century the city also grew as one of Britain's main hubs of transatlantic trade with British North America and the British West Indies.