Hohentwiel Fortress

The Hohentwiel in Singen is an extinct volcanic cone in the Hegau region near Lake Constance, crowned by the ruins of one of Germany's largest fortresses. Spread over about 9 hectares (22 acres), the ruins offer sweeping views across the Hegau volcanoes and Lake Constance and, on clear days, all the way to the Swiss Alps. More than a thousand years of history make it a rewarding stop between Stuttgart and Zurich.

From volcano to fortress

The Hohentwiel rises to 696 meters (2,284 feet) and is made of phonolite, a volcanic rock that cooled inside a volcano millions of years ago. Ice Age glaciers later scraped away the softer rock around it, leaving the steep cone you see today.

A castle stood here as early as around 915, and in about 970 Duke Burchard III and Duchess Hadwig founded a monastery on the hill. From 1521 Duke Ulrich of Württemberg expanded the castle into a fortress, and in 1538 it passed fully to Württemberg. Its finest hour came in the Thirty Years' War, when commander Konrad Widerholt held out through five sieges without the fortress ever falling. French troops finally took it in 1799 and demolished it in 1801.

What to see

• Lower and Upper Fortress: Explore bastions, gates and massive walls on the western slope and the summit.
• The Princely House: remains of the medieval castle and ducal residence
• The view: The operators call it the most beautiful panorama in Baden-Württemberg, with Lake Constance and the Alps on the horizon.
• Vineyards: The Olgaberg and Elisabethenberg slopes are among Germany's highest vineyards.

In summer, the ruins host the open-air Hohentwiel Festival, a tradition dating back to 1969. A 3D app shows how the fortress once looked.

Tickets and opening hours

As of October 2026, according to the official website:

• April 1 to October 15: daily 9:30 a.m. to 6:30 p.m. (last entry 5:30 p.m.)
• October 16 to March 31: weekends and public holidays only, 10 a.m. to 4 p.m. (last entry 3 p.m.)

Admission is €5 for adults, €2.50 reduced and €12.50 for families. Bring cash: card payments are currently not possible.

How to get to the Hohentwiel

Singen lies about 30 miles northwest of Zurich Airport and roughly two hours by car from Stuttgart. Singen station has direct Deutsche Bahn connections from Stuttgart and Zurich, and regional trains from Lake Constance; the Deutschlandticket covers regional services on the German side. On weekends and holidays, the on-demand Hohentwiel-Taxi (line 8) runs about hourly from the station up the hill. Parking at the visitor center is very limited; free parking is available at the former state garden show grounds and the Festplatz, about a 35-minute walk away.

Practical tips

• The fortress is not wheelchair accessible, though the visitor center is.
• Dogs are welcome on a leash; drones are banned.
• A kiosk serves drinks and snacks daily from 11 a.m. to 6 p.m., weather permitting.
• Wear sturdy shoes and allow two to three hours including the climb.

Is it worth visiting? Yes, if you enjoy castle ruins, hiking and big views. Combine it with Reichenau Island, a UNESCO World Heritage Site on Lake Constance, or the Rhine Falls just across the Swiss border.