(Mandarin Oriental Website) Though many of the most famous sites in Prague are located in the Staré Mesto and Nové Msto, the Prague Castle and much of the city's most atmospheric walks are found on the other side of the River Vltava in the Malá Strana neighborhood. One of these unique buildings is the Mandarin Oriental Prague, housed in a converted Dominican monastery from the 14th century. Even hotel group's signature holistic spa experience, with water-based facilities such as a vitality pool and two saunas, is set in an area of architectural heritage. The spa's entry, a glass walkway, both displays and preserves the remnants of a Gothic church found during the hotel's renovation. A stroll around the Malá Strana will give guests ample opportunities to indulge in the city's famous brews and hear some splendid classical tunes.

(Mandarin Oriental Website) Though many of the most famous sites in Prague are located in the Staré Mesto and Nové Msto, the Prague Castle and much of the city's most atmospheric walks are found on the other side of the River Vltava in the Malá Strana neighborhood. One of these unique buildings is the Mandarin Oriental Prague, housed in a converted Dominican monastery from the 14th century. Even hotel group's signature holistic spa experience, with water-based facilities such as a vitality pool and two saunas, is set in an area of architectural heritage. The spa's entry, a glass walkway, both displays and preserves the remnants of a Gothic church found during the hotel's renovation. A stroll around the Malá Strana will give guests ample opportunities to indulge in the city's famous brews and hear some splendid classical tunes.

(The Liberty Hotel Website) A grey stone structure emerges at the Boston side of the Longfellow Bridge, harkening back to a time far before the Massachusetts General Hospital and Red Line MTA rail were the major players in this area. The looming façade belongs to the Liberty Hotel, now a popular playground for adults, but the former home to the Charles Street Jail. The enormous atrium is beautifully preserved, the lighting fixtures providing a modern aesthetic with a historical slant. The architecture of the former jail has been brilliantly reconceived as an urban one-stop shop: the nightclub is in the former "drunk tank," cocktail areas occupy the surviving catwalks, and two different eateries can be found in rooms with original jail cell details. A VirtualTourist.com member noted that the location, once ideal for preventing prisoner escapes, is now very convenient for exploring Boston: stroll around Beacon Hill, cab to Newbury Street, or take the T's Red Line to Cambridge.

(La Purificadora Website) One of the first projects to catalyst the converted hotel trend beyond monasteries and jails is La Purificadora in Puebla, Mexico. The city of Puebla, located 100 km (62 miles) east of Mexico City, was one of the most important colonial cities in Mexico. It served as the site for the significant victory over France that established a holiday adults all over the world enjoy celebrating: Cinco de Mayo. The city is also a UNESCO World Heritage site due to its range of preserved architecture styles. Unlike the majority of converted hotels that are housed in refurbished palaces, monasteries, or convents, the structure housing La Purificadora was born in 1884, as an ice factory where water was bottled and purified for ice production. The archeologists and architects kept the building's original use in mind when designing the hotel, incorporating clear glass, pools, and open spaces, and allowing the adjacent church of St. Francis to be seen from almost any public area of the hotel. It is a unique and talented group who managed to make a modern and open space so effortlessly coexist within a city of colonial landmarks, making La Purificadora truly the benchmark for a successful converted hotel.

(Wanderlust Hotel Website) While many visitors to Singapore assume sticking to hotels located on Marina Bay is their best bet, other areas of the city are exploding with the unique flavor that can only come from a city with such a variety of ethnic backgrounds. In the Little India neighborhood, Wanderlust Hotel is a great example of this trend. Built in a former schoolhouse, the hotel is part of the Unlisted Collection, which also includes Singapore's New Majestic Hotel and Shanghai's The Waterhouse at South Bund; all three are converted hotels. Wanderlust added something new to the mix by giving each of the four floors to a local design firm, resulting in four different themes: Industrial Glam for the Lobby Level, and Eccentricity, Is It Just Black and White? and Creature Comforts for the three floors of rooms. In addition to the high design experience, the hotel also offers a rustic French restaurant, Cocotte, filled with communal tables and food on shared plates.

(Hotel Hospes Website) Visitors to the Andalusia area of Southern Spain usually stay in Seville and make a quick trek to see the Mezquita in Cordoba, the former Mosque that was then converted into a Christian Cathedral in the center of Cordoba's old town. However, the Hospes Palacio del Bailio provides a truly unrivaled experience and definitely warrants an overnight stay. Housed in a 16th century palace, the hotel's architecture provides an immersion into Moorish influence and architecture usually only afforded in Morocco. Beautifully decorated with modern fixtures and a soothing color scheme of neutrals, the hotel embraces its architecture and history while providing guests with all of the modern amenities, like internet and Korres bath products, we've grown accustomed to in the 21st century.

(Four Seasons Hotel at Sultanah) The ochre exterior is just the first of many signifiers that the Four Seasons Hotel at Sultanahmet is a unique experience. The building, a former Turkish prison, is not only an astounding neoclassical structure, but it is also conveniently located between the Hagia Sofia and the Blue Mosque, two of Istanbul's greatest treasures. The hotel has elements that harken back to the 1918 structure, such as reused tiles from the building's former incarnation, and the landscaped courtyard, which once served as the prison's exercise yard. Another great benefit to this spot: guests are allowed to use all the amenities at the Hotel's sister property, the Four Seasons Hotel Istanbul at the Bosphorus.

(Montpelier Plantation Website) While the Caribbean has long been known for its luxurious resorts and variety of water activities, the history of the area is lost on many of its visitors. Fortunately, some properties in the region are finding ways to incorporate the history of the area into the guest experience. On the island of Nevis, a British holding that is often reached by traveling to nearby St. Kitts, the Montpelier Plantation provides a luxurious retreat on a former 18th century sugar plantation. Though it is no longer producing much sugar, it still attracts quite a bit of buzz - Princess Diana and both her sons visited shortly after her separation from Prince Charles.

(Hotel del Casco Website) Originally built in 1892 and located 22 km (14 miles) north of Buenos Aires, Hotel del Casco is a restored neoclassical palazzo. Formerly an aristocrat's summer home and later a warehouse for stored goods, the palazzo has been meticulously renovated to its original splendor. The builders made every effort to keep the original structure and preserve the building's unique neoclassical details, such as its traditional marble entrance staircase and large columns. The interior patio (pictured above) is a distinctive feature of the building, creating that grand "great room" feeling that has long been forgotten. VirtualTourist.com members noted that the suburb of San Isidro, where Hotel del Casco is located, is a charming residential neighborhood with a great cathedral and several old mansions that make the visitor feel transported back in time.

(Quinta Real Zacatecas Website) While many have stayed in a refurbished factory or a renovated palace, few travelers can say they stayed adjacent to an authentic bullfighting ring. The Quinta Real Zacatecas, located in Zacatecas, Mexico, hasn't seen any action of that kind since 1975, but the architecture of the building and various levels allow for a communal space rarely achieved in hotels today. While visiting Zacatecas, VirtualTourist members recommend strolling the city streets or taking the teleferico (cable car) up the Cerro de la Bufa and enjoying the views from above.

(The Conservatorium Hotel Websi) Compared to other hotels on our list, the Conservatorium Hotel has been open the shortest amount of time, but its building has been in use much longer! The hotel has kept the historic façade of Amsterdam's former music conservatory, but there is nothing "student budget" about these five-star accommodations. The building's glass façade and construction instigated an urban regeneration of the Museumplein, the once dodgy area also known as the Museum Quarter. The hotel is perfectly situated for a morning spent wandering the Rijksmuseum and the Van Gogh museum, and an afternoon window shopping designer stores such as Filippa K, Iceberg, and G. Star on nearby P.C. Hooftstraat.