The Trinity Square, also referred to as the Holly Trinity Square, is located in the very Castle District of Budapest, on the left bank of the Danube. This fortunate location turns the Trinity Square into one of the most frequented squares in the capital of Hungary, since the sights it is marked by or it neighbors on count as some of the highest rated tourist attractions of Budapest.

Thus, the Church of Mathias overlooks Szentharomsag ter from one side, but the north side of the square is where the old Buda Town Hall is located. This late 17th century building might not match the Church of Mathias in magnificence, but it is a place of considerable architectural and historical significance.

The name of the square comes from an early 18th century column erected here in memory of the victims who died during two plague epidemics.