Surrounded by inhabited areas Rupp Hill stands around 250 meters high somewhat isolated from other hills of Buda as the easternmost peak of Csíki Hill Range. The hill is located in Pösingermajor borough of District 11. It is one of the habitats in Budapest where flora of rocky meadows were preserved covering over 8 hectares. Rupp Hill has been a natural reserve under the supervision of the city.

The hill was named after former owner György Rupp and later Ferenc Pösinger established an estate there in 1688 giving name to the whole borough.

The base of the hill is made up of Triassic dolomite with scarce marlstone on the top. Over the past centuries hydrothermal transformation of dolomite allowed for mining wall paint additives in the hill and abandoned mining caves are still there. The hill is rich in minerals, e.g. goethite, hematite and calcite with an exceptionally great volume of quartz.

The history of the hill, its geology and wildlife is introduced by a nature trail with 5 stations. Stepping off the trail is forbidden as protected plants are abundant in the forest.

Rupp Hill is a popular research area among botanists. Besides a Scots pine plantation flora is native. On the northern slopes we can find spots of oaks and hornbeams with a rich shrub layer while the hill top and the southern slopes are covered by rock meadows, various sorbus species, downy oaks, St Lucie cherry trees with lady orchids as typical along the Csíki Range.

The orchid-rich hill is a habitat for 38 protected plants. Herbaceous plants include species like pheasant's eye, iris pumila, burning bush, small and greater pasque flower, White Helleborine, European Michaelmas-daisy, Hungarian thistle, fragrant wallflower and onosmas, St Bernard's lily, scorpion vetch and Squarrose Knapweed.

The hill offers great values for zoologists also since the favorable environment maintains a fairly rich fauna as well. Protected beetle species include bush cricket, Strawberry Seed Beetle, stag beetle, southern festoon, mourning cloak and hermit. Amphibian species are represented by European tree frogs and agile frogs and reptiles include various lizards, juniper skinks and smooth snakes. Various species of birds, such as chiffchaffs, nightingales, collared flycatchers, short-toed treecreepers, blackcaps, golden orioles, sparrowhawks and common buzzards can find a shelter in the forest. Common swifts nesting in the nearby residential area also frequently visit Rupp Hill to hunt.

The meadow on the top of the hill offers a great scenic view over Budapest and Budaörs. The highest point is marked by a metal stake with a flag.