This article originally appeared in Travel+Leisure.

The first time you visit a country, you likely spend time in its capital or most famous city. You want to see the well-known sites-whether it's the Eiffel Tower, or the Acropolis, or Machu Picchu. But if you really want to go deeper into a country, consider adding a few days in a "second city" and slowing things down, taking your time to savor what makes that place unique. To round up some compelling places to add to your travel wish-list, T+L polled our A-List of veteran travel advisors about their favorite underrated, non-capital cities.

Thessaloniki, Greece

My go-to destination as an alternative to Athens would be Thessaloniki, which is undoubtedly considered to be Greece's second-capital. With a fascinating history, a complex cultural tapestry that is the result of generations' worth of interplay between different peoples, excellent cuisine, beautiful sea views, and a vibrant local character, Thessaloniki is easy to love. The city's different neighborhoods are like small worlds onto themselves, each with its own distinct history and atmosphere. All around the city, old meets new as Roman monuments and Byzantine churches overlook modern buildings and busy streets.-Christos Stergiou, True Trips