The Birkenstock Madrid is the original that started it all. Known as the Birkenstock Fitness Sandal in Europe, this design tones the foot and calf muscles while improving circulation. This timeless one strap women's sandal features the famous Birkenstock contoured footbed, fully adjustable strap and shock absorbing EVA sole. This Birkenstock footbed of sustainable cork, featuring pronounced arch support, a deep heel cup and a roomy toe box and covered with a suede liner makes the Birkenstock Madrid a sandal you'll want to wear again and again.