Edinburgh, Scotland

Edinburgh Castle sits on Castle Rock, the plug of an extinct volcano, with the Royal Mile running downhill from its gates through the old town to Holyrood Palace — a walk that covers most of Edinburgh's must-see sights in a single, mostly downhill stretch.

Like Dublin, Edinburgh draws a steady stream of Scottish-American families tracing clan history, and several Highland day tours built around specific clan regions or castles are easy add-ons from the city. A rental car opens up the Highlands more broadly for families staying a week or longer.

The Edinburgh Festival Fringe, throughout August, turns the city into the world's largest arts festival and is a genuinely unique reason to visit — at the cost of the year's highest hotel rates and thickest crowds. Outside the Fringe, May through September brings Edinburgh's best weather for walking the Royal Mile and any Highland day trips.

Edinburgh splits into the medieval Old Town, dominated by the castle on its volcanic rock outcrop, and the Georgian New Town's planned streets and squares — the contrast between the two is part of what earned the city its UNESCO World Heritage status. The Royal Mile connects the castle to Holyrood Palace, and the Scottish Highlands are close enough for a day trip, though most visitors extend their stay to do the Highlands justice.

Three nights covers the Old and New Towns, typically as the start or end of a broader Scotland trip. It suits history and whisky enthusiasts particularly, and visiting during the August Fringe Festival brings significant crowds and higher prices worth planning around.

Getting there: About 6.5 to 7.5h nonstop — Delta flies year-round from New York, with seasonal nonstops from other cities. Since Edinburgh, Scotland is best visited May to September, or August (Fringe Festival), we build the itinerary around that window rather than treating the flight search and the calendar as separate decisions.

Edinburgh's Old Town grew upward rather than outward for centuries, constrained by defensive walls, which produced some of Europe's earliest high-rise tenement buildings — structures reaching ten stories or more as early as the 1500s, centuries before the term 'skyscraper' existed anywhere else. The city is built on the remains of extinct volcanoes; Arthur's Seat, the main peak overlooking the city, and Castle Rock, on which Edinburgh Castle sits, are both volcanic plugs, giving the city a genuinely dramatic geology underneath its architecture. Edinburgh is also the birthplace of the modern literary festival concept and holds UNESCO City of Literature status, home to Robert Louis Stevenson, Arthur Conan Doyle and, more recently, J.K. Rowling, who wrote much of the early Harry Potter series in Edinburgh cafés — The Elephant House among them — within sight of the Gothic spires and graveyard headstones (including one reading 'Tom Riddell') widely believed to have influenced her. The Edinburgh Festival Fringe, the world's largest arts festival, takes over the entire city every August, when the population effectively doubles and every available room, from proper theaters to converted church basements, becomes a performance venue. Scottish cuisine runs on haggis, neeps and tatties as the traditional centerpiece, alongside a genuinely serious whisky culture rooted in centuries of regional distilling tradition.