In 250 BC, a Celtic tribe called the Parisii settled on a marshy island in the Seine — the same stretch of river where, 2,000 years later, an iron tower built for a temporary exhibition would become the most visited paid monument on earth. Paris doesn't just have history; it has layers upon layers of it, compressed into 105 square kilometres and inhabited by 2.04 million people. That density is precisely what makes it extraordinary — and exactly what makes it so easy to get wrong. The typical two-day visit skims the surface: a selfie at the Eiffel Tower, a bewildered shuffle through the Louvre's Grande Galerie, and a cruise along the Seine. None of it wrong, all of it incomplete. A private tour in Paris doesn't just move you faster through the highlights — it fundamentally changes what you understand about what you're seeing. This guide explains why, and how to structure the experience that actually does this city justice.