Southern Europe’s record summer crowds and unrelenting heat are fuelling an unprecedented backlash from residents in major destinations. Paris, which welcomed 48.7 million visitors last year, now faces protests over the ‘Disneyfication’ of Montmartre after the Sacré-Cœur alone drew 11 million sightseers. Similar slogans telling visitors to leave have appeared in Marseille, Barcelona and Venice as locals complain of round-the-clock noise, soaring housing costs and clogged public services. Municipalities are responding with caps and penalties aimed at moderating the flow rather than halting it. Marseille, where hotel occupancy reached 85 % over the mid-August long-weekend—up 12 points from 2024—is considering entry limits for several neighbourhoods after already restricting access to the Calanques National Park to 400 people a day. Palma de Mallorca allows only three cruise ships to dock daily and has frozen hotel capacity at 12,000 beds, buying obsolete properties for conversion into housing or green space. Across the Mediterranean new behaviour codes carry bite. Fines range from €150 for littering in Portugal’s Algarve to €3,000 for street drinking in Spain’s Balearic Islands, while Venice levies a €10 fee on day-trippers and is closing two cruise terminals by 2026. Greece will start daily quotas at the Acropolis, and French resort towns have expanded bans on smoking and beachwear away from the shore. Economists warn the push-back could ripple through an industry that supplies roughly one-tenth of the European Union’s output. Yet hotter, longer summers—recent heatwaves ran up to 4 °C above historical averages—are lengthening the tourist season and intensifying pressure on water supplies, waste systems and public health, creating what analysts call a feedback loop between climate change and overtourism. Local officials and tour operators say the path forward lies in dispersing demand and raising standards rather than simply raising drawbridges. “Our economy depends on tourism, so we must make it sustainable,” said Pedro Homar, head of tourism for Palma. With visitor numbers still climbing, Europe’s marquee destinations are racing to strike a balance between welcoming travellers and preserving liveable communities.