It is the westernmost part of the Transdanubian Mountains. Stone pillars, gully-holes, dolinas, and gorges vary the surface of the Keszthely Hills, composed of dolomite. Kovácsi Hill and Tátika are the basalt region of the Keszthely Hills. Monadnocks, basalt plateaus, polygonal basalt pillars, more than 10-meter high walls decorate the landscape. The basalt corridor of Kovácsi Hill and the basalt dolinas, which are considered as pseudokarst phenomena and have small ponds in their depressions, are very rare and therefore very interesting. Caves can be found inside the hills. There are many natural formations in the area, for example, the cave of Cserszegtomaj and the ‘Csodabogyós' cave in the wooded hillside of Balatonederics. In the course of an organised tour, you can admire the passages and the dripstones in the depths of the earth. The length of the cave, known so far, is over five thousand meters and its depth is one hundred and twenty-one meters. Its giant, spectacular fissures show the individual layers as natural geological profiles. In the halls called ‘Hanging garden' and ‘Fairyland', there are hundreds of stalactites, and about 50-60 breath-taking stalagmites higher than 1.5 meters. In addition, you can see unique-shaped formations on large surfaces.
The original tree communities were cleared in many parts of the mostly wooded areas of Keszthely Hills and fast-growing black pines were planted to replace them. Keszthely Hills are almost unparalleled from a botanical point of view. The heat-tolerant plant communities of the areas facing south mix with the flora of cool gorges, which results in unique communities, such as the inherited-soiled karst scrub forest, where the heat-loving manna ash lives together with beech trees, which prefer colder territories. Closed dolomite grassland communities developed on the treeless karst and the breaks. The ancient beech forest of Tátika Hill, which is a reserve forest today, has been protected since 1953. The Keszthely Hills have almost 80 rare plant species including the Hungarian leopard's bane, which lives in southern gorges, the bear's ear, which can be found on the northern slopes, the Calamagrostis varia, and several pasqueflowers, orchid and pink species. The basket of gold, the martagon lily and the iris variegata live on grasslands. The fauna of the area also needs to be mentioned, since there are many rarities among the insect and butterfly species. The carabus problematicus that lives here is a rare insect species nationwide. Inhabitants of the gallery forests include the black woodpecker, the lesser spotted woodpecker and the European green woodpecker. The European nightjar and the mistle trush can often be observed here too. Peacefulness is favourable to a number of protected species; alpine longhorn beetles, stock doves, and northern ravens also live here. The Keszthely Hills are also regarded as the favourite habitat for edible dormice, beech martens and bats; for the latter, mainly because of the caves. There are several nature trails in the area. The Old Dormouse's Nature Trail (Pele apó tanösvénye), whose existence is due to the Balaton Uplands National Park, has one of the most beautiful sceneries. This nature trail, which starts from Szépkilátó in Balatongyörök, was inaugurated a few years ago, and it is primarily recommended for children. It is 8.5 km long, contains 38 stops, can be reached from the most popular sites of the region, and shows the natural values of the forest habitats between Balatongyörök and Balatonederics. The information boards provide information in Hungarian and English languages. A publication was issued on the area and the nature trail, which describes the natural values of the Keszthely Hills and functions as a guidebook containing maps. It is worth visiting the ‘Nagymező' (Great field) located in Gyenesdiás, which is a kind of regional excursion centre in the area. Here, you can find many interesting things to explore! Nagymező has always been popular, it functioned as a rest area at the end of the 1800s, and it is not surprising that the Festetics Family's ducal carriage road went through it. The countryside changed around 1880, at this time the black pine was naturalised so that the dolomite barrens could be afforested. In the 1950s, the forestry expanded the territory of the Nagymező, and in the 1960s a regional excursion centre was designed, rain shelters, benches, seats were set up, and, in 1976, a forest exercise trail was built. The popularity of Nagymező is undiminished with 50-60 thousand visitors per year. There are many group programmes, and a number of companies hold their meetings and gatherings there.