Once a museum of applied arts and protected as a historical monument since 1966, the Martin-Gropius-Bau has evolved into one of Berlin’s best-known exhibition halls. The building’s legacy blends with its current role as a space for major cultural programs, presenting changing exhibitions that span art, design, and contemporary ideas.
Source - https://en.wikipedia.org/wiki/Martin-Gropius-Bau
Not far away from Schloss Tegel (at the "große Malche") you can take a look at the oldest tree in Berlin, an oak which has been growing there since about 1192 (so it's actually older than Berlin itself). The name ("fat Mary") allegedly stems from the brother Humboldt who named the tree after their overweight cook.
The longest stretch of the Berlin Wall still in existence, painted by artists in 1991 and restored in 2009, after years of decay. At Mühlenstraße, next to the river Spree. The murals are painted on the east side of the wall after the fall of Communism; so they are not from the Cold War, during which murals could only be painted on the west side. Make sure not to miss the famous mural of a car seemingly crashing through the wall with Leonid Brezhnev and Erich Honecker kissing above it. It is actually on the back side of the gallery (it is facing away from the street.) It is just inside the entrance of the Eastern Comfort Hostel, near the east end of the gallery.
Museum established in 1888, with a collection of 3,500 instruments.
One of the oldest buildings in Charlottenburg and actually the reason for the whole city to be built.
Built 1859-1866 this is one of the most architecturally stunning synagogues in Germany to survive both the Nazi era and the war.
150-200 m along the Wiener Straße (bypassing the fire house and the public swimming pool) from U-Bahn Görlitzer Bahnhof, the park is famous for the Turkish families barbecuing on summer weekends, failed contemporary art and relaxed atmosphere of students. It does have a reputation of being full of pickpockets and drug dealers though and the police makes regular visits to this place to check on the situation.
Huge technical museum, on a former railroad depot, featuring from ancient water and wind mills to computer pioneer Konrad Zuse's inventions, a collection of old to new vehicles of all types -bicycles, boats, trains, etc - and the interactive Spectrum science center with various hands-on experiments. There's an actual C-17 "Candy Bomber" airplane hanging on its façade. The railroad and aeronautical sections are hard to beat.
The largest aquarium in Germany with over 9000 animals that are presented on three storeys in a historic building. Aquarium Berlin is found on the premises of the Zoo, but can also be visited separately. One of the best places on a rainy day with children.
German historical museum covering everything from pre-history up to the present day. One can spend many, many hours here! The building from 1695/1730 was the Zeughaus (Arsenal) until 1876.
The Bierpinsel ("beer brush") is a building in Steglitz which resembles an observation tower and is famous for its pop-art appearance. The futuristic, landmarked building was built from 1972 to 1976 and has since been used as restaurant, night club, bar, radio station and art café.
This heritage-protected 120-m-long pedestrian tunnel below the river Spree was the first ferro-concrete tunnel in Germany that has been built using pneumatic caissons. Two beaches can be accessed via the tunnel which are not far from its south entrance.
A splendid 15th-century Gothic church with many fine accoutrements.
The building of one of Berlin’s oldest breweries is a ravishingly beautiful and heritage-protected industrial monument.
The meeting point of one of the leading oppositions against the GDR regime and is a great Neogothic church. Also the only ecumenical Lord's supper with Protestants and Catholics together took place in the Gethsemanekirche (2003).
The city's Protestant cathedral and the burial place of the Prussian kings. You can climb to the top and get a view of the city.