Main attractions
Römerberg is a central, old place in downtown Frankfurt. It features various buildings and a church from the 14th and 15th century (in theory; the buildings were mostly destroyed during World War II but completely rebuilt afterwards). The Römer itself is the town hall of Frankfurt. Cafés and shops can be found at the square itself and in the vicinity. A definite tourist attraction. Within walking distance of the Zeil shopping area and the Main river, it is located just north of the Eiserner Steg bridge. Next to the cathedral, at the Archäologische Garten, you can see the remains of the Roman settlements that gave this place its name. At the Römer, you can also visit the Alte Nikolaikirche (12th century church, current form since the 15th century). Walking towards the Main river, you can also see the Rententurm (Wharfinger's Tower), an old 15th century fortified tower in late Gothic style, which is connected to the Saalhof, an old 12th century castle building that was later modernized but never completely destroyed.
Dom (Saint Bartholomeus' Cathedral): the main cathedral, built in Gothic style in the 14th century. From 1562 to 1792, emperors of the Holy Roman Empire were crowned in the cathedral. Located right next to the Römerplatz (U4 Dom/Römer).
The Eiserner Steg (Iron bridge) - Relatively well-known bridge for pedestrians, built in 1869. It is just a minute away from the Römer. Crossing the bridge leads you to Sachsenhausen and provides good views of the skyline.
Hauptwache: A public area (officially called "An der Hauptwache") that is often considered the central hub of Frankfurt's modern downtown area due to its importance as a public transportation station and its central location, right between the main shopping street (Zeil), the Rossmarkt (another public square), and the Eschenheimer Tor. The place is named after a Baroque building ("Hauptwache") located more or less in its centre. The building was constructed in 1730 to house the local city militia, as Frankfurt was an independent city at the time. When Frankfurt became part of Prussia, the building gradually lost its original function. Since 1905, it has instead been serving as a café ("Café Hauptwache"). Other attractions include the Katharinenkirche, and the Palais Thurn-und-Taxis.
Alte Oper (Old Opera) - Renaissance Opera Building in the center of the city (take U6 or U7 station Alte Oper, or any line to Hauptwache and walk a few minutes); a busy square with fountains can be found in front of it. Originally opened in 1880, it is not used for operas any more since the rebuilding after the war, but for concerts, congresses, and similar "fancy" events.
Börse (Frankfurt Stock Exchange): Frankfurt stock exchange building, still in use, see the bull and bear statues just outside. You cannot enter the building unless you have registered for a guided tour in advance.
Paulskirche (St. Paul's Church) was the seat of the first democratically elected parliament in Germany in 1848. It is located just north of the Römer place.
Sachsenhausen: crossing one of the bridges from the city centre you reach the Sachsenhausen part of the city south of the Main river. The old town part, Alt-Sachsenhausen, at Affentorplatz is famous for its old cider bars (see the "Drink" section for more information). You can also walk along the river bank or visit the Schweizer Straße (see the "Buy" section).