For a city the size of Potsdam, the size of this park and the number of buildings on its grounds…read moreare impressive, clearly constructed centuries ago to be a playground for royalty.
Sanssouci Palace was designed and built between 1944-47 for Frederick the Great of Prussia to be a summer palace, in a Rococo style and is rather small with only 10 rooms, more of a casual residence rather than a full-blown palace. The terraced gardens and fountains were modeled after Versailles with grape vines imported from France, with Frederick being a proponent of harmonizing art with nature. The extensive gardens and park grounds were built after the main palace was completed following a similar horticultural theme, entailing planting fruit trees and establishing nurseries, and building a number of smaller reception rooms, temples, decorative buildings, fountains, etc. Ironically even though fountains were built around the park, the systems only fully worked once hydraulic technology advancements allowed broader installation of functional water pumps across the park in the mid-19th century. Further expansion and development occurred under later rulers, when Charlottenhof Palace was built.
The park itself is free to visit, though tickets need to be purchased for individual sites within (palaces, picture gallery, Orangerie) or together as a combo ticket--some buildings (including the castles) require timed entry so book in advance for best time selections. Options are available on the website or in person at the ticket counters in Schloß Sanssouci or at the info booths in the park.
Walking from east to west, edge to edge of the park can take about 40 minutes walking straight across. However if you're walking around trying to see the various large and small sites, you could spend a full day within the park. The paths are paved, pretty flat, and disability friendly. Not all of the larger buildings have bathrooms so plan accordingly in advance. Sanssouci Palace is on the east side and Neues Palais is on the west side and it's easily ~25-30 mins to walk between the two. Charlottenhof and Orangerieschloß are respectively in the more south and north areas in the park.