Of the rest of the land, 51.1% is settled (buildings or roads) and the remainder (6.3%) is non-productive (rivers or lakes).

[4] The municipality is located in the Rorschach region on the left bank of the Alter Rhein, an old channel of the Rhine, which is also the Austrian border.

The blazon of the municipal coat of arms is Gules three Fishes Azure nainaint in band on a Bend wavy Argent[5] Rheineck has a population (as of 31 December 2020) of 3,404.

Of the foreign population, (as of 2000[update]), 49 are from Germany, 318 are from Italy, 460 are from ex-Yugoslavia, 101 are from Austria, 42 are from Turkey, and 111 are from another country.

[8] The historical population is given in the following table:[3] The Löwenhof at Rorschacherstrasse 15 is listed as a Swiss heritage site of national significance.

Additionally, the Schlosslandschaft Rorschach / Alter Rhein, a number of castles in a region along the Rhine river, is also a designated as part of the inventory.

The Schlosslandschaft is shared between Berg, Goldach, Mörschwil, Rheineck, Rorschacherberg, St. Margrethen, Steinach, Thal and Tübach.

Additionally, the Rheineck–Walzenhausen mountain railway links the station to Walzenhausen, 272 m (892 ft) above Rheineck, once or twice an hour.

[14][15][16][17] Rheineck is the easterly end of the Swiss shipping services on Lake Constance, and the town's landing stages are located behind the railway station on the Alter Rhein channel.