The local government of Warsaw’s suburban Jabłonna is housed in a building built in the second half of the 18th century—the former inn. In 1774, the youngest of the king’s brothers, Michał Poniatowski (1736–1794), came into possession of the residence of the bishops of Płock in Jabłonna. As soon as the next year he commenced the building of a palace as designed by the Royal Architect Domenico Merlini. No later than in the year 1778 and quite possibly in parallel with the building of the palace, which would make it around 1774, work on building this residential complex was taken on by another prominent architect of the Polish Enlightenment, Szymon Bogumił Zug. In as much as Merlini designed the most important building of the complex and laid the underpinnings for the spatial layout of the complex, it was Zug who completed the whole of the project, building the remaining key elements for the venture of the king’s brother. Zug built them on the basis of an axial layout. The main axis ran along the entry avenue toward the palace and onward to the Vistula River through a depressed open shoreline basin. Symmetrically, two residential annex buildings were built on both sides of the palace—the eastern one was the Royal Annex while the western one was the Guest Annex. The palace foreground was a vast courtyard, where the entry was accented by a pair of obelisks and figures of chimeras. The broad entry avenue was intersected by a perpendicular road on which Zug placed two small pavilions, known as the Szeffleroski and Margrave pavilions. Opposite the entrance to the palace, closing the main compositional axis from the northeast, was an inn encompassed by wings consisting of complexes of building designated for peasants. The inn building should be ranked as a part of the stream of Classical architecture, primarily distinguished by rationalism in terms of both functionality and frugality of form. Located on the central axis and in spite of being emphasized by a grand arcade, the main entrance led to a relatively small entrance hall chiefly serving circulation, not representational purposes. It provided access to the remaining parts of the building—the tavern and guest rooms linked with direct connections to the stables, and stairs to leisure and guest rooms as well as to the cellars. A door led to the kitchen and bakery behind the entrance hall. Large, vaulted cellars were located beneath a part of the rooms. The solution used in shaping Jabłonna inn volume should be considered very successful. It was compact and covered by a tiled pitched roof, which is a response to Polish climatic conditions. The frugal and purist solution for the façades has an ordered rhythm of windows that are provided with moderate decorative elements. In spite of the lack of accuracy as to the dating of the time of building of the inn as well as the fact that it was not taken into account in a monograph devoted to Zug by Marek Kwiatkowski, it seems to absolutely confirm that the author of the inn in Jabłonna was S. B. Zug and that the building was built by 1778 and quite possibly as one of the first in the complex.