A closer look
Why bother waiting in a depressing customs line when you can simply launch yourself off a cliff into another sovereign nation? The 'Limite Zero' zipline connects Sanlúcar de Guadiana in Spain to Alcoutim in Portugal, letting tourists hurl themselves across the Guadiana River at 50 miles per hour. Because Portugal operates in a different time zone, you technically travel back in time by one hour during the 60-second ride, making it the most aggressive border crossing on Earth.






