Lake Constance

Lake Constance (German: Bodensee) sits at the foot of the Alps and is shared by three countries: Germany, Austria and Switzerland. The Swiss shore, spread across the cantons of Thurgau and St. Gallen, offers a calmer lakeside break with harbour promenades, medieval towns, castles and a cycling route that hugs the water.

How big is Lake Constance?

The lake covers roughly 536 km², stretches up to 63 km in length and 14 km in width, and reaches a depth of around 250 m. Its surface lies about 395 m above sea level. It has two basins: the broad Obersee and the smaller Untersee in the west, linked by a stretch of the Rhine called the Seerhein. The Rhine flows in near Bregenz and leaves through the Untersee. The lake also supplies drinking water to about 4.5 million people.

What is there to see on the Swiss side?

• Romanshorn is the main Swiss port on the lake, with a pleasant harbour promenade and ship landing.
• Rorschach lies at the lake's southernmost point and was once one of its key harbours.
• Arbon has a medieval old town and a lakeside castle, extended between 1510 and 1518 under Bishop Hugo von Hohenlandenberg, with the Saurer Museum close by.
• Steckborn and Ermatingen mark the stretch of the Untersee with the densest cluster of castles and fortified houses.
• Gottlieben, on the Seerhein, is known for one of the prettiest village squares in Switzerland.
• Kreuzlingen is the largest Swiss town on the lake and borders German Konstanz directly.

Across the border, the island of Mainau, nicknamed the Island of Flowers, shows over half a million blooming plants each year.

How do you explore the lake?

By boat, ideally. Rhine and Untersee services run under the operator URh, and in season ships link ports in all three countries. The alternative is the Bodensee cycle path around the lake; the Swiss stage runs from Rorschach through Arbon and Romanshorn to Kreuzlingen. It is mostly flat and works well for families.

When should you go?

Summer is swimming season, with lakeside pools and beaches at places such as Altnau, Arbon and Staad. Spring and early autumn bring fewer crowds and comfortable cycling weather. Timetables and fares change every season, so check the operators' websites before you plan a cruise.

Frequently asked questions

Which countries share Lake Constance? Germany, Austria and Switzerland. There is no single formally agreed border across the whole water surface.

How deep is it? About 250 m at the maximum; sources quote values between 251 and 254 m.

Can you cycle all the way around? Yes. The Bodensee cycle route circles the lake through all three countries, and its Swiss section connects Rorschach, Arbon, Romanshorn and Kreuzlingen.

Which Swiss town works best for a day trip? Choose Steckborn or Ermatingen for castles and quiet lanes, Romanshorn for the harbour and promenade, and Arbon for a medieval old town.