Many European hotspots have been battling with overtourism and huge crowds of visitors for years.Countless clips have circulated online showing packed streets in Italy, crowded beaches in Spain and major attractions heaving with people. Some are struggling with the vast number of visitors more than others, and there are now destinations where tourists outnumber the locals.Data compiled by Eurostat and analysed by Greek Reporter has revealed the exact locations where you're more likely to bump into another holidaymaker than a permanent resident. 1. South Aegean islands The South Aegean islands, including Santorini, proved to be the most tourist-dense Iconic blue domed buildings, stunning coastlines and rich histories – it's not surprising the South Aegean islands are attracting masses despite having a population of around 326,000. The region, which includes Santorini, Mykonos and Rhodes, saw the highest tourist saturation of any region in the European Union in 2024. The data focused on regions with a population of between 150,000–800,000, according to The Independent. During the time period, tourists spent 127.2 nights for every resident. A whopping 41.5 million overnight stays were recorded.Most other regions across the EU saw less than 15 overnight stays per resident. 2. Ionian Islands A long queue of tourists waiting to see Melissani Cave in Kefalonia in June Located along the western coast of Greece, the Ionian Islands cover dreamy destinations like Corfu.There were more than 20.5 million overnight stays in the region which has a local population of 200,000.This summer seems to have been particularly busy for some Greek spots.The Daily Mail visited Kefalonia, the largest of the Ionian Islands, in June and found tourists swarming around certain attractions and causing long queues despite the summer holidays still being weeks away.3. Bolzano, Italy Bolzano in South Tyrol, Italy, logged 68.9 tourist overnight stays per residentBolzano, in South Tyrol, northern Italy, is known as the gateway to the Dolomites due to its convenient location surrounded by stunning mountain views. The much-loved spot logged 68.9 tourist overnight stays per resident.Italy overall has been bustling with visitors this summer and viral videos shared online revealed shoulder-to-shoulder crowds in Rome, snaking ferry queues on Lake Como and heaving train platforms in Cinque Terre.4. Adriatic coast, Croatia Croatia's Adriatic coast also proved to be particularly busy Croatia's Adriatic coast proved to be the fourth most tourist-dense with 67.5 overnight stays per resident.Officials in the Adriatic resort of Makarska have been forced to patrol beaches in the early hours of the morning to collect unattended items left behind by holidaymakers attempting to save spots on the sand. Municipal crews teamed up with wardens and harbour staff to carry out the clear-outs.5. Balearic Islands, Spain Residents of the town of Soller in the island of Majorca staged a protest against mass tourism in the Balearic Islands earlier this monthThe Balearic Islands consist of popular spots including Mallorca, Menorca and Ibiza.Drawing in hordes of tourists with their balmy beaches and beautiful weather, the area saw 60 overnight stays per resident.Earlier this month, thousands of campaigners took to the streets of Soller, in Mallorca, to protest against mass tourism.Residents have complained of rising housing costs from holiday rentals or foreign nationals' second homes as well as congestion in once-quiet towns and villages. 6. Crete, Greece The Greek island of Crete brought in 55.6 overnight stays per residentAnother Greek spot, Crete, followed with 55.6 overnight stays per resident.Around 6.6 million visitors flocked to the island last year, according to Greek Trip Planner.The port of Souda is popular with cruise ships heading to Chania for its charming old town and harbourside restaurants. Least tourist-dense: Mayotte Whereas Mayotte, a French island territory in the Indian Ocean, proved to be the least tourist-denseBut not everywhere has been overrun by tourists.The French island territory of Mayotte, located in the Indian Ocean, saw the lowest ratio of overnight visitors per resident. In 2024 there were 0.5 stays per resident.