(CNN) — It's an unsung region in the heart of Europe, but Poland's Lower Silesia is packed with natural wonders, historic cities, splendid palaces and unsolved mysteries.
This southwest corner of the country has undergone a cultural change since World War II when the predominantly German-speaking province of the Free State of Prussia became part of the Republic of Poland.
Its rich and sometimes hard history makes it a fascinating region for exploration and one of the most interesting parts of Poland to visit. Here are 11 highlights to kick-start a tour of Lower Silesia.
With beautiful fairytale architecture and a picturesque Old Town, Wrocław is a standout not just of Lower Silesia but also Poland as a whole.
Highlights of this economic, cultural and educational powerhouse include the stunning medieval town hall, charming Ostrów Tumski (Cathedral Island) and Centennial Hall -- the UNESCO-protected masterpiece of early Modernism.
It's a vibrant and welcoming city with a lively food and drink scene.
The Baroque hall of the Aula Leopoldina in the Museum of the University of Wroclaw is a frescoed delight, while the best views are from the university's Mathematical Tower. (Museum of the University of Wrocław, Plac Uniwersytecki 1, 50-137 Wrocław, Poland; +48 713 752 618) Extra tip: Wrocław is also home to the oldest and most impressive zoo in Poland with a unique Afrykarium -- an oceanarium dedicated to the fauna of Africa. (Wrocław Zoo, Wróblewskiego 1-5, 51-618 Wrocław, Poland; +48 713 407 119)
2. Książ Castle
Książ Castle on a hill in the forest outside Walbrzych hides a secret past, some of it yet to be discovered.
Perched on a hill surrounded by forest, Książ Castle is one of the most impressive sights in the country. (Książ Castle, Piastów Śląskich 1 58-306 Wałbrzych, Poland; +48 746 643 834)
Its imposing grandeur and hidden secrets have spread its fame far beyond Poland. In 2015 it made global news headlines after two treasure hunters claimed a Nazi train full of gold was buried under the castle. A subsequent dig came up empty handed, but the castle's legend -- as a rumored planned headquarters for Hitler -- persists.
The castle still puzzles researchers with its vast network of underground tunnels dug by Nazis between 1943 and 1945.
A year after treasure hunters alerted authorities to an underground 'Nazi gold train', a team started excavations in the hope of solving the WWII mystery.
Extra tip: Also near the town of Walbrzych is the Underground City Osówka, hollowed into the Owl Mountains. (Underground City Osówka, Świerkowa 29 d Sierpnica, 58-340 Głuszyca, Poland; +48 748 456 220)
Project Reise, as it was called, was a mysterious Nazi scheme involving the construction of a network of enormous underground passages with an uncertain purpose. Wałbrzych itself was once an industrial coal-mining center with a picturesque market square, interesting architecture and a palm house containing many species of tropical plants.
Set in a valley encircled by the Sudetes mountain range, Kłodzko is a mix of different cultural influences, all of which left their architectural marks. Many of the buildings bear a striking resemblance to the architecture of the nearby Czech Republic.
There is a splendid Gothic stone bridge often referred to as a mini version of Prague's Charles Bridge because of its similarity to the famous Czech counterpart.
Kłodzko also has a beautiful Baroque Old Town with an amazing City Hall and grandiose Gothic Church of Assumption.
With breathtaking views, a mighty appearance and impressive underground tunnels, Kłodzko Fortress is one of the highlights of this charming city. (Kłodzko Fortress, Grodzisko 1, 57-300 Kłodzko, Poland; +48 748 673 468) Extra tip: In the countryside outside Klodzko, Pałac Kamieniec is a boutique hotel set in a beautiful renovated 18th-century Baroque palace. (Pałac Kamieniec, Kamieniec 47, 57-300 Kłodzko, Poland; +48 748 692 045).
4. Churches of Peace in Jawor and Świdnica
The Church of Peace in Swidnica is a timber-framed edifice built in the mid 17th century.
The Churches of Peace are timber-framed religious buildings constructed by Silesian Protestants after the conclusion of the 1648 Peace of Westphalia that ended religious wars in the region.
Originally there were three churches but only two, in Jawor and Świdnica, have survived. In 2001, they were added to the UNESCO World Heritage List. As the largest timber-framed churches in Europe, the Churches of Peace have impressive interiors with Baroque ornaments and splendid altars.
Świdnica's colorful Old Town is perfect for walking. It's home to the Gothic cathedral of St. Stanislaus and St. Vaclav, famed for the highest tower in Silesia.
Extra tip: Cafe Łukowa is a decent stopping point for great coffee and tasty desserts. (Cafe Łukowa, Łukowa 8, 58-100 Świdnica, Poland; +48 748 520 888)
5. Ząbkowice Śląskie
Its Polish name might not mean much to outsiders, but virtually everyone will have heard of its former moniker -- Frankenstein. Some researchers speculate that Mary Shelley's famous novel "Frankenstein" could've been inspired by the gruesome events that took place in this little town around 1606.
Plague fell upon the area and Frankenstein lost about one third of the population. The town's archives contain a story about the trial of a gang of eight gravediggers who supposedly made a poisonous powder from infected corpses to spread the deadly disease all over the city.
Legend perhaps, but it's easy to believe after walking around the sleepy historic town with the romantic ruins of a 14th-century castle and crooked, hilly streets. The name was changed in 1946 after the region passed to Poland.
One of the most interesting sights in Ząbkowice Śląskie is the unique medieval Leaning Tower nicknamed the "Silesian Pisa." (Leaning Tower, Świętego Wojciecha 7, 57-200 Ząbkowice Śląskie, Poland)
The reason for its leaning remains a mystery. Some blame the earthquakes of the 16th century while others think that it was made this way on purpose to make the city more unique.
Extra tip: The nearby Owl Mountains offer a refreshing escape, with numerous hiking trails as well as great panoramas from the observation tower on the Wielka Sowa peak.
6. Skull Chapel in Czermna
Skull Chapel in Czermna houses a macabre collection of 3,000 skulls and bones that belonged to the victims of wars and diseases.
Outside it may look like a small charming Baroque chapel. Inside, it's a palace of death.
That's because its walls and ceiling are decorated with 3,000 skulls and bones belonging to the victims of wars and diseases.
There are also about 20,000 bones underneath in the crypt.
The Skull Chapel was founded in 1776 by Father Wacław Tomaszek, a local priest inspired by the Capuchin cemetery in Rome. (Skull Chapel in Czermna, Stanisława Moniuszki 8, 57-350 Kudowa-Zdrój, Poland; +48 605 540 927)
It took him 18 years to collect and clean the human remains and erect the chapel. Tomaszek's own skull was added to the altar in 1804.
Extra tip: The charming little spa town of Kudowa-Zdrój is set right on the border with the Czech Republic and is surrounded by beautiful natural scenery. W Starym Młynie is one of the town's best Polish restaurants. (W Starym Młynie, Fredry 10, 57-350 Kudowa-Zdrój, Poland; +48 748 663 601)
7. Vang Stave Church
The Norwegian wooden church of Vang was transplanted to Poland in the mid 19th century.
The Karkonosze Mountains of Lower Silesia hide an unexpected attraction in a charming wooden Norwegian stave church. It was built in the 12th century in Vang parish of southern Norway, but bought by famous Norwegian painter J.C. Dahl in 1841 to save it from demolition.
With the blessing of King Frederick William IV of Prussia the church was re-erected on its present site in the mid-19th century. Vang Stave Church is a unique example of Scandinavian religious architecture, built without a single nail and featuring ancient runic inscriptions.
The Karkonosze Mountains offer plenty of picturesque valleys and scenic panoramas, particularly via the cable car to the Szrenica peak in Szklarska Poręba.
Extra tip: The traditionally built Chata Karkonoska restaurant in Karpacz offers a flavorsome spread of typical Polish dishes. (Chata Karkonoska, Wolna 4, 58-540 Karpacz, Poland; +48 757 618 277)
8. Lubiąż Abbey
Lower Silesia is renowned as a land of abbeys, but perhaps the most famous is Lubiąż, the largest Cistercian monastery in the world. It dates from medieval times when the first monastery was built near the Oder river. Its subsequent history is checkered, notably during World War II.
It is in the Lubiąż Abbey that the Nazis established the secret research laboratories and developed the V1 and V2 rockets. (Lubiąż Abbey, Pogodna 38, 56-100 Lubiąż, Poland)
The Soviet army moved in after the war, but thorough restoration in more settled times has put the abbey and its breathtaking Baroque interiors back on the tourist map.
Extra tip: The Krzeszów Abbey is another spectacular Lower Silesian monastery complex with a stunning Baroque basilica containing the miraculous painting of Holy Mary the Merciful dating back to the 13th century. (Krzeszów Abbey, plac Jana Pawła II 1, 58-420 Krzeszów, Poland; +48 757 423 279)
Then there's the beautiful Henryków Abbey, which contains the "Book of Henryków" with the first recorded written phrase in the Polish language. (Henryków Abbey, plac Cystersów 1, 57-210 Henryków, Poland)
9. Jelenia Góra valley
With a large number of spectacular palaces and beautiful historic gardens, the Jelenia Góra valley is often nicknamed the "Polish Loire" after the world-famous French region packed with attractions.
A good place to start is the market square of the picturesque town of Jelenia Góra, famous for its charming colorful burgher houses.
Among the best sights are the Neo-Gothic Karpniki Castle, the splendid Wojanów Palace, the stately Łomnica Palace and the majestic ruins of the medieval Chojnik Castle. (Chojnik Castle, Zamkowa, 58-570 Jelenia Góra, Poland; +48 757 556 394) Extra tip: One of the best restaurants in Jelenia Góra is Cytrynowy Pieprz, which serves Italian and European meals with a contemporary touch. (Cytrynowy Pieprz, Szkolna 1, 58-500 Jelenia Góra, Poland; +48 600 542 601)
10. Błędne Skały
Nicknamed the "Polish Narnia," Błędne Skały's labyrinth of rocks, caves and gorges is the perfect setting for a fantasy.
The magical "Polish Narnia" is a mesmerizing labyrinth of giant rocks in the Stołowe Mountains National Park.
The unusual mushroom-shaped boulders, mysterious caverns and picturesque gorges are the perfect setting for a fantasy movie. It's no surprise, then, that the film "Chronicles of Narnia: Prince Caspian" was partly shot here.
The stunning Kamieńczyk Waterfall -- the highest waterfall of the Polish Karkonose Mountains -- is another location from the film.
Extra tip: The best views of the surrounding valleys and Sudetes range can be seen from the panoramic terrace on the top of Szczeliniec Wielki, the highest peak (919 meters) in the Table Mountains National Park.
Relaxing atmosphere, beautiful walking paths, luxurious health resorts and proximity to the majority of the regional attractions make the small city of Polanica-Zdrój one of the most popular spa destinations in Poland.
Many visitors are keen to sample the medicinal water from Polanica's Pijalnia Wód Mineralnych (Pump Room) set in the picturesque Zdrojowy Park. Extra tip: One of the best coffee shops in town with a wide variety of desserts is Caffe Bohema. (Caffe Bohema, Zdrojowa 39, 57-320 Polanica-Zdrój; +48 792 444 752)