One of Greece’s most famous landmarks is trialing limiting its daily visitors, starting today.

The Athens Acropolis archaeological site attracts visitors from around the world keen to marvel at the ancient cultural spot. Going forward, visitors will be capped at 20,000 a day, with a booking website keeping track of footfall and enforcing an hourly slot system.

In an interview with Greek radio station Real FM in August, Greek culture minister Lina Mendoni said that the Acropolis currently has up to 23,000 daily visitors, calling this a “huge number.”