Basilica of Sts. Peter and Paul, Reichenau

The Gnadensee is part of Lower Lake Constance (German: Untersee), the western part of the lake.

Reichenau is a municipality in the district of Konstanz in Baden-Württemberg in Germany. It is located partly on Reichenau Island with its famous abbey and on the northern shore of the Untersee section of Lake Constance. The island has historically been the center of the community. The administrative seat of the municipality is in the village of Mittelzell. A causeway built in 1838 connects the isle with the mainland. The municipality consists of the settlements Niederzell, Mittelzell und Oberzell on the island as well as Lindenbühl and Waldsiedlung on the shore. The municipality encompasses the estates of the former Reichenau Abbey, which was secularized in 1757. Today Reichenau is characterized by the market gardening of fruits and vegetables and also known for its psychiatric hospital, established in 1913, a teaching hospital of the University of Konstanz. Reichenau can be reached via the Bundesstraße 33 running from the Bundesautobahn 81 to Konstanz. It has also a railway station on the High Rhine Railway (Hochrheinbahn) connecting Basel and Konstanz.

Reichenau Abbey was a Benedictine monastery on Reichenau Island (known in Latin as Augia Dives). It was founded in 724 by the itinerant Saint Pirmin, who is said to have fled Spain ahead of the Moorish invaders, with patronage that included Charles Martel, and, more locally, Count Berthold of the Ahalolfinger and the Alemannian Duke Santfrid I (Nebi). Pirmin's conflict with Santfrid resulted in his leaving Reichenau in 727.

Reichenau Island (German: [ˈʁaɪçənaʊ]) is an island in Lake Constance in Southern Germany. It lies almost due west of the city of Konstanz, between the Gnadensee and the Untersee, two parts of Lake Constance. With a total land surface of 4.3 km2 (1.7 sq mi) and a circumference of 11 km (6.8 mi), the island is 4.5 km (2.8 mi) long and 1.5 km (0.93 mi) wide at its greatest extent. The highest point, the Hochwart, stands some 43 m (141 ft) above the lake surface and 438.7 m (1,439 ft) above mean sea level. Reichenau is connected to the mainland by a causeway, completed in 1838, which is intersected between the ruins of Schopflen Castle and the eastern end of Reichenau Island by a 10-metre-wide (33 ft) and 95-metre-long (312 ft) waterway, the Bruckgraben. A low road bridge allows the passage of ordinary boats but not of sailing-boats. In 724, the first monastery was built on the island by bishop Pirmin, and Reichenau quickly developed into an influential religious, cultural, and intellectual center. During the Early and High Middle Ages, the Reichenau Abbey was one of the significant monasteries across the Frankish Empire. Because of its historical importance and the exceptional quality of the architecture and artwork found in the island's three churches and abbey, Reichenau was declared a World Heritage Site in 2000.

The Untersee (German for Lower Lake), also known as Lower Lake Constance, is the smaller of the two lakes that together form Lake Constance and forms part of the boundary between Switzerland and Germany.

Allensbach is a municipality in the district of Konstanz in Baden-Württemberg in Germany. Allensbach is located between Konstanz and Radolfzell on Lake Constance.

Louisenberg Castle is a castle in the municipality of Salenstein of the Canton of Thurgau in Switzerland. It is a Swiss heritage site of national significance.

Arenenberg is an estate with a small chateau, Schloss Arenenberg, in the municipality of Salenstein at the shore of Lake Constance in Thurgau, Switzerland that is famous as the final domicile of Hortense de Beauharnais. Today it houses the Napoleonmuseum. It is a Swiss heritage site of national significance.

Eugensberg Castle is a castle in the municipality of Salenstein of the Canton of Thurgau in Switzerland. It is a Swiss heritage site of national significance.

Salenstein is a municipality in Kreuzlingen District in the canton of Thurgau in Switzerland. Salenstein was the home village of Napoleon III, who lived at Castle Arenenberg in his youth.

The Church of Saint George is a Roman Catholic Church. It is part of Reichenau Abbey founded in 724, located on the island of Reichenau on Lake Constance in southern Germany. The island is home to the churches of Saint Mary, Marcus, Peter and Paul. The Church was built in the late 9th century to house the relic head of Saint George, a gift from Pope Gregory II, which commemorated a visit to Rome by Abbot Hoito in 896.The church is owned and run by the Catholic Church of Saint George Fund. The church interior is decorated with wall paintings that depict stories and figures from scripture and was designed for those who dedicate their lives to prayer and worship.

The Liebesinsel ("Love Island") is a small, uninhabited island on Lake Constance in Germany.