Tvaren
Coordinates: 58 ° 45 ′ 56 ″ N , 17 ° 24 ′ 53 ″ E
Tvären is a circular bay in the Baltic Sea in the municipality of Nyköping in the province of Södermanland County near Studsvik in Sweden .
The bay has a diameter of about 4 km and is located above an old, buried and no longer visible impact crater . The crater has a diameter of about 2 km. Its age is estimated to be around 455 million years.
The asteroid (7771) Tvären is named after the bay.