olar hot water heating is gaining popularity in Slovenia.
Tourism
Slovenia offers tourists a wide variety of natural and cultural amenities. Different forms of tourism have developed. The tourist gravitational area is considerably large, however the tourist market is small. There has been no large-scale tourism and no acute environmental pressures.
The nation's capital, Ljubljana, has many important Baroque and Vienna Secession buildings, with several important works of the native born architect Jože Plečnik.
At the northwestern corner of the country lie the Julian Alps with the picturesque Lake Bled and the Soča Valley, as well as the nation's highest peak, Mount Triglav in the middle of Triglav National Park. Other mountain ranges include Kamnik–Savinja Alps, Karavanke and Pohorje, popular with skiers and hikers.
The Karst Plateau in the Slovenian Littoral gave its name to karst, a landscape shaped by water dissolving the carbonate bedrock, forming caves. The best-known caves are Postojna Cave, with more than 28 million visitors, and the UNESCO-listed Škocjan Caves. The region of Slovenian Istria meets the Adriatic Sea, where the most important historical monument is the Venetian Gothic Mediterranean town of Piran while the settlement of Portorož attracts crowds in summer.
The hills around Slovenia's second-largest town, Maribor, are renowned for their wine-making. The northeastern part of the country is rich with spas, with Rogaška Slatina, Radenci, Čatež ob Savi, Dobrna, and Moravske Toplice growing in importance in the last two decades.
Other popular tourist destinations include the historic cities of Ptuj and Škofja Loka, and several castles, such as the Predjama Castle.
Important parts of tourism in Slovenia include congress and gambling tourism. Slovenia is the country with the highest percentage of casinos per 1,000 inhabitants in the European Union. Perla in Nova Gorica is the
