3Lisbon, Portugal

Lisbon has transformed from a quiet European capital into a tourism hotspot in just over a decade. While the boom has boosted the economy, it has also created backlash among locals. Central neighborhoods like Alfama and Bairro Alto have seen massive rent hikes as apartments are converted into short-term rentals.

Longtime residents feel pushed out, while narrow streets struggle with overcrowding. Protests against gentrification and “touristification” have grown more common in recent years.