Arenfels Castle owes its present appearance to a prominent master builder: Ernst Friedrich Zwirner was a pupil of Karl Friedrich Schinkel. Zwirner, who was entrusted with the completion of Cologne Cathedral, was commissioned by Count Friedrich Ludolf von Westerholt-Gysenberg to modernise the castle from 1849 to 1858. Extensive changes had already been made about 300 years before the neo-Gothic reconstruction: In place of the 13th-century Arenfels Castle, the new three-winged Renaissance castle was built in the second half of the 16th century. Friedrich Ludolf would have liked to retain the style of the complex in the 19th century, but cathedral master builder Zwirner prevailed with his new formal language. During the battles for Remagen Bridge in the Second World War, the building fabric was considerably damaged. Most of the war damage has been repaired today. The beautiful interiors of the castle have been restored, and the imposing cast-iron staircase from the Sayner ironworks is particularly worth seeing.

Arenfels Castle, with its location in the middle of the vineyards, is a romantic venue for weddings, family celebrations and corporate events. There are a variety of events throughout the year (concerts, wine tastings, knights' dinners, Christmas market, etc.) as well as various themed tours. The castle is home to cosy hotel rooms, the Genusskontor (vinotheque & delicatessen) and a self-service wine garden. Located directly on the Rheinsteig, it is also a popular destination for hikers.