1. Market Square (Marktplatz) in Heidelberg is a lively and bustling square located in the heart of the historic old town. It is surrounded by beautiful historic buildings, including the Heidelberg Town Hall (Rathaus) and the Church of the Holy Spirit (Heiliggeistkirche). The square is a popular gathering place for both locals and tourists, with a variety of shops, cafes, and restaurants nearby.

One interesting fact about Market Square is the famous Heidelberg Christmas Market, which takes place here each year during the holiday season. The market features traditional wooden stalls selling handicrafts, decorations, and delicious holiday treats like Glühwein (mulled wine) and roasted chestnuts.

2. The Market Square is open to the public at all times, as it is a public square. The shops, cafes, and restaurants around the square may have varying opening hours. You can contact the Heidelberg Tourist Information Office at +49 6221 142 239 for more information.

3. There is no ticket required to visit Market Square as it is a public space. The square is easily accessible by public transportation, with several tram and bus stops nearby. If you are coming from the Heidelberg Hauptbahnhof (main train station), you can take a tram to Bismarckplatz and then walk to Market Square. Parking is limited in the old town, so it is recommended to use public transportation if possible.