3 Best Sights in Budapest, Hungary

There are about 200 accessible caves in Budapest (some open, some not) but Pálvölgyi and Szemlőhegyi are the most popular. Both provide a long network of underground walking trails through narrow passages filled with crystal formations, stalactites, and stalagmites. The Pálvölgyi Cave stretches around 18 miles, making it the longest cave network in Budapest and one of the longest in Hungary. It is also one of the most beautiful. Breathe in at Szemlőhegyi as this cave is known for its mineral-infused air. The caves must be visited on a guided tour that lasts just under an hour. Pálvölgyi and Szemlőhegyi can be visited on a combined ticket. Mátyáshegy cave, just opposite Pálvölgyi, is a bit more intense, with some climbing required and caving equipment provided, so it is best suited to the fit (and the brave).

Adventure-seekers should book a three-hour adventure caving tour (21,000 HUF) with Caving Under Budapest (caving.hu), which offers the chance to climb and crawl through these caves.

Used as a wine cellar during the 16th and 17th centuries and then as an air-raid shelter during World War II, this 16-meter (52-foot) deep, 1,200-meter (3,900-foot) long labyrinth—entered at Úri utca 9 below an early-18th-century house—has a fascinating history. Today, the cave system has been turned into something of a novelty attraction, which gets mixed reviews. Exhibits include elaborately costumed wax figures attending a "haunted" masked ball, the mist-filled tomb of Count Dracula (who is said to have been imprisoned here), and the "Labyrinth of Darkness," a pitch-black section of the maze. It's a good escape on a hot day—it's a consistent 20°C in the caves—or join the 6 pm evening tour, when the winding corridors are illuminated only by oil lamp.

This atmospheric church built into a cave—one of several in the hill—lies just north of the Gellért Thermal Baths. Mass is still held here (the church is run by the Pauline monks) and worth attending if so inclined, but it is also worth a look for its novelty value. Note: it was rebuilt in faux-cave style in the '90s so it is not quite as authentic as it could be.