Böhmischer Prater
The about 150-year-old Böhmische Prater, which is situated in the 10th district of Vienna, is perfectly geared for family trips. Whether you like hiking in the recreation area Laaer Berg or enjoying the amusement park with its variety of fairground rides, there is something for everyone and all tastes. What had first been a works canteen of the Wienerberger Ziegelwerke later became the first restaurant and was soon followed by many more. Moreover some showmen established first funfair rides. A quarter of the district of Favoriten was from Böhmen and Mähren, which were part of the crown lands, and employed at the Ziegelwerke. It is due to them, that the amusement park got the name Böhmischer Prater. The area's popularity would not diminish until World War II when it was bombed to the ground. It took a long time to rebuild it the way it looks today. Children mostly like the so-called Ringelspiel but there are also attractions like the Jumping Tower, minigolf or bumper car. Additionally you can visit events like the Kasperltheater or spend time strolling around the flea market. There are also restaurants like Zum Werkelmann or booths where you can get sweets or the famous hungarian speciality called Lángos which is really worth trying. For trips in the evening there is the Casino Monte Laa. If you are lucky, you are able to see the renaissance fair that sometimes takes place there. Source: http://www.wien-vienna.at/bprater.htm 
Lainzer Tiergarten (U4 Hütteldorf, 55B, 60, 60B)
The Lainzer Tiergarten is the last remaining piece of ethnic Wienerwald. It is located in the West of Vienna reaching a size of 2.450 hectares. Having once been the imperial hunting ground it has nowadays become a famous destination for excursions. While enjoing the unique beauty of nature with its variety of endangered animals and manifold plants you can additionally learn about art in the specifically for empress Elisabeth built Hermesvilla.
It is very important to protect nature because it is living space of rare animal species and therefore the Lainzer Tiergarten is mostly kept in its natural state. Characteristics of the area are the impressive oak and beech forests. A great attraction is the free-living wildlife stock. There are many recreation offers you can enjoy.
Source: MA 49-Forstamt und Landwirtschaftsvertrieb der Stadt Wien
Lake Neusiedl (Neusiedler See)
Lake Neusiedl is about a 45 min drive away from Vienna, but definitely worth a day trip. Its surroundings form a unique landscape in the heart of Europe, one that not only is protected by strict nature conservation laws but was also named a World Heritage Site. Typical, rare flora and fauna combined with the interaction of Germanic, Slavic and Finno-Ugric influences allow you to experience a one-of-a-kind landscape and culture.
The second largest steppe lake in Central Europe is not only a top spot for sailors, wind surfers and aquatic athletes of all kinds, but also very popular among cyclists and seaside tourists.
http://en.wikipedia.org/wiki/Lake_neusiedl
Laxenburg
Schloss Laxenburg really is worth a visit. With its park landscape, its old castle, the blue court as well as the Franzensburg it is one of the most beautiful places around Vienna. Laxenburg is also the place where empress Sisi spent her honeymoon and gave birth to crown prince Rudolph.
Today there are lots of leisure facilities which attract over one million visitors per year. No matter if you want to enjoy nature, do some sports or learn about culture. You can even combine these things by using the cultural walk. Laxenburg's history dates back to the 13th century when the name Lachsendorf, which was the village's original name, was first mentioned. It was in 1306 when the Habsburger acquired the castle who gradually made the place their residence for spring and summer. The economic interests were thus neglected and the aera was mainly used for recreational matters. Therefore many buildings for the aristocracy, which were brought there by the imperial family, were erected in the surroundings. Due to Duke Albrecht II pleasure gardens and vivaria were created. After the siege of Vienna in 1683 there was again an enormous building boom. The greatest building activity however was under empress Maria Theresia which lead to a fundamental change of the castle's appearance. The most famous building is the Franzensburg which was ordered by emperor Franz II and now contains a museum. Other attractions are the baroque parish church, the Grünne-Haus and the Kaiserbahnhof. For those interested in film, situated in Laxenburg there are the modern film archives, austria's biggest film collection. Source: http://www.schloss-laxenburg.at/ 
Mayerling
Memories of Crown Prince Rudolph
The location was the hunting lodge of Crown Prince Rudolph, a noble raised hide near the township of Alland, which was in the possession of the Heiligenkreuz monastery since 1550.
Prince Rudolph was the only son of Elisabeth and emperor Franz Joseph, who rained the Habsburg empire 68 years, and therefor the heir apparent of the Austrian and Hungarian empire.
After purchasing the property in 1886 Rudolph converted it into a hunting lodge.
1889 a tragic episode in Austrian history occurred at this little village, only a 30-minute drive from Vienna. Crown Prince Rudolph committed suicide together with his secret lover Marie Alexandrine Freiin von Vetsera. Rumours surrounding the mysterious suicide of the Crown Prince and his companion persist even to the present day. Today, visitors to Mayerling not only receive information on the current status of research into the deaths of the two aristocrats, they can also visit the former hunting lodge, which was later turned into a Carmelite convent by emperor Franz Joseph.
http://en.wikipedia.org/wiki/Mayerling
Prater (U1, U2 Praterstern; U2 Messe-Prater)
The Viennese 'Prater' is divided into the world-famous historic amusement park and the huge recreational area, which once was the imperial hunting grounds. Take a ride on the roller coasters,enjoy the view from the Viennese ferris wheel, walk through the park or go for a run.
Schönbrunn Palace (U4 Schönbrunn)
Schönbrunn is the former imperial 1,400-room Rococo summer residence of the Habsburgs and is one of the major tourist attractions in Vienna. In 2009 over 5 million people visited the whole Schönbrunn complex with Tiergarten Schönbrunn, Palmenhaus, Wüstenhaus and the Wagenburg. The vast area includes the palace and numerous side buildings, as well as spacious gardens and parks. The impressive Baroque art work has been named a UNESCO World Heritage Site.
http://en.wikipedia.org/wiki/Schoenbrunn_Palace
Tiergarten Schönbrunn (U4 Hietzing)
http://www.marionettentheater.at/
Steinhofgründe (46B, 146B Feuerwache am Steinhof)
What might at first seem as yet another park in an otherwise dull city, is actually a beatiful and mostly untouched recreation area, and as such a perfect place to visit. Especially if you like nature and wild animals, you'll find it can be a pretty interesting area, and if you're lucky you might even get to watch a wild deer stroll around the trees. The Steinhofgründe are recreation areas of the size of 42 hectares, in which you can spend time hiking, flying a kite, having a picnic or just relaxing. In winter you can even luge or cross-country ski. For children there is also a playground.
The Steinhofgründe are located in the 14th district of Vienna between Johann-Staud-Straße and Heschweg, which is near Baumgartner Höhe. Some time ago they were the gardens of the Otto-Wagner-Spital which was openend in 1907 and designed by the famous Jugendstil architect Otto Wagner. In the 1970s there were plans to construct new buildings there which was prohibited by a referendum. Since then the forestry commission office takes care of them. Today there are again discussions about using the area as building ground instead of preserving the beautiful nature.
The area can be reached very easily by bus. There are four different entries: Feuerwache Steinhof, Großes Schutzhaus Rosental, the corner Heschweg/Rosentalgasse or entries by the Otto-Wagner-Spital. Unfortunately dogs are not allowed. Note that there are different opening hours depending on the saison.
http://www.wien.gv.at/umwelt/wald/erholung/steinhof.html Türkenschanzpark (10A, 37A, 40A, 41, N41) The 150.000 m² spanning Türkenschanzpark belongs to the 18th district and lies between Peter-Jordan-Straße and Hasenauerstraße, surrounded by Max-Emmanuel-Straße and Gregor-Mendel-Straße. The area’s history dates back to 1683 as the Turks entrenched themselves there which is reffered to as the Second Siege of Vienna. The architect Heinrich von Ferstel and the Stadtgartendirektor Gustav Sennholz played a key role in the establishment of the park itself, its look, and were revered by the people living in the surroundings. The place was supposed to be an English landscape garden. Today there are many merits that can be emphasized. Besides the beautiful pond arrangement there are waterfalls and fountains to enjoy as well as the variety of botanic specialities from faraway countries. The latter can be found there not just because of the specific soil but also because of the University for soil culture which is situated near the park. Another attraction is the Paulinenwarte, named after princess Pauline Metternich. This tower is located in the middle of Türkenschanzpark and offers a wonderful view over Vienna. Note that there are particular opening hours only at a few weekends a year. Strolling around the park you will spot many memorials for famous people like Arthur Schnitzler or Adalbert Stifter. For those who are too energetic to just stroll about there are leisure time facilities like Streetball or Beach Volleyball.
In 1888 Türkenschanzpark was ceremoniously opened by the emperor Franz Joseph I. At the beginning of the 20th century the park was enlarged through inclusion of the nearby sandpit, which allowed plants from other climate zones to grow. This new part was opened in 1910 by mayor Josef Neumayer.
Once a year in summer there is an art festival called Montmartre which is really worth a visit. There you can find various kinds of art and music for both children and adults.
So there is something for everyone and if you finally get hungry you can have a meal at the park’s restaurant Mayerei which offers traditional Viennese delicacies as well as seasonal Schmankerl.
Vienna Woods (Wienerwald)
The Vienna Woods are Vienna’s green leisure oasis. It offers an amazing experience of nature, gentle hills with precipitous, rugged canyons, idyllic vineyards, calm woods and mystic meadow landscapes. The whole surrounding creates an impressive romantic environment.
http://en.wikipedia.org/wiki/Vienna_Woods
Wachau
One of the most beautiful river valleys with a landscape of high visibility formed by the Danube River is awaiting your discovery. The Wachau was inscribed as "Wachau Cultural Landscape" in the UNESCOList of World Heritage Sites in December 2000 under category (ii) for its riverine landscape and under category (iv) for the medieval landscape that depicts architectural monuments, human settlements, and the agricultural use of its land.
Allow yourself to be enchanted and inspired by the beauty of the surrounding landscape.
Popular highlights of the Wachau are Canons' Abbey in Dürnstein, the abbeys Goettweig or Melk. Set in the Wachau and depicting the politics of the times, the epic German poem "Nibelungenlied" was written around 1200 AD. Fragments of this epic was discovered in the monastic library of Melk.
The graceful landscape is at its most beautiful in May, when hundreds of apricot trees in the fruit and wine gardens along the Danube bloom in magnificent snow white.
http://en.wikipedia.org/wiki/Wachau