The Grand Tour was a rite of passage for the aristocracy, and the adventuresome spirit behind it lives on in modern European itineraries. A longtime travel publisher traces the evolution of this fantastic voyage. Then Rick Steves' Europe guidebook researcher Cameron Hewitt takes a look back on the ways travel has evolved over the past quarter century. And as the Sagrada Família stretches ever closer toward completion, one of the project's architects helps us understand what Gaudí's ambitious creation means to Barcelona and Catalonia.

Debbie and Michael Campbell, aka the "Senior Nomads," offer listeners their expert advice on traveling full-time during retirement. And tour guides from Britain, Poland, and Germany reflect on how politics and media shape public conversation about current events within their own and neighboring nations.

An American expat in Oslo shares some of the quirks and customs of life in his adopted home. Then, a wilderness and history author recounts what he found exploring four blank spots on the US map. And an ethnobotanist describes the healing properties of different kinds of herbs around the world — some of which might be growing in your own backyard.

Tour guides from the north and south of Ireland let us in on their picks for sights and experiences that will make a first trip to the Emerald Isle a memorable one. Plus, an Irish American singer explains the importance of music to the Irish and how the island's history is found in its folk ballads and songs.

Get tips for experiencing what remains of Aztec culture in modern-day Mexico City. Then hear about what recent excavations in Pompeii are revealing about first-century life in the Roman Empire. And join a historian in considering how the cultures of France's many neighboring countries have long shaped and enriched its identity.

Rick engages a panel of European tour-guide friends to find out how they're responding to recent changes in the political relationship between their countries and the US, and to discuss the home-grown populist pressures that have been gaining followers in Europe. Plus sculptor Richard Rhodes recommends European destinations with especially impressive stonework — from famous buildings to little-known sites that have endured through the ages.

Estonia's medieval charm, beautifully preserved naturescapes, and Baltic culture are cultivating a burgeoning tourism scene. Bradt guidebook author and Estonian authority Neil Taylor lets us in on the abundant appeal of the former Soviet republic. And a certified Cicerone — that's "craft beer expert" — takes us on a tour of European suds and helps us tap into the best pints across the continent.

Astronomer Philip Plait — who fell in love with Saturn after first viewing the gas giant, with its mesmerizing rings and moons, through a telescope as a child — shares some of the amazing discoveries we've made about the planet in recent years. Then actor Martin Sheen describes how his travels in the developing world have opened his eyes, and his heart, to the needs of others. And a Florence-based tour guide and culinary expert lets us in on where to find the best food in her adopted home.

An Easter Island-based travel writer and lecturer lets us in on what life is like on the cruise-ship circuit. Then journalist Lyse Doucet recounts her career as the BBC's chief international correspondent and delves into the issues her profession grapples with today.

Bradt guidebook author Joshua Zukas, who focuses exclusively on Vietnam, shares why he enjoys challenging misconceptions about his adopted home. And a writer who has spent his life captivated by the mighty Mississippi River takes us on a virtual tour of America's great waterway, from Minnesota to the Gulf of Mexico.