Tucked away in a small park off Heister Strasse on the south bank of the Main, the Grüne Sosse Denkmal — Green Sauce Monument — is a row of seven small free-standing greenhouses, each containing one of the seven herbs that make up the canonical Frankfurter Grüne Sosse. Designed by the sculptor Olga Schulz, it was unveiled in 2007 with the express purpose of finally settling local arguments about exactly which herbs belonged in the sauce.
The herbs themselves grow inside the seven brushed-steel pavilions: borage, chervil, cress, parsley, salad burnet, sorrel and chives. The monument is open all hours and free; the surrounding park is a pleasant ten-minute detour from a Museumsufer walk, and the Frankfurt Green Sauce Festival (Grüne-Sosse-Festival) is held nearby on the Roßmarkt every May, when seven local restaurants compete for the prize of the best version of the sauce.